@article {2502,
	title = {Near-Infrared Absorbing Azo Dyes: Synthesis and X-ray Crystallographic and Spectral Characterization of Monoazopyrroles, Bisazopyrroles, and a Boron-Azopyrrole Complex},
	journal = {Journal of Organic Chemistry},
	volume = {74},
	number = {15},
	year = {2009},
	note = {ISI Document Delivery No.: 476XOTimes Cited: 5Cited Reference Count: 69Li, Yan Patrick, Brian O. Dolphin, David},
	month = {Aug},
	pages = {5237-5243},
	type = {Article},
	abstract = {Symmetric 2,5-bisazopyrroles 2(a-d) were synthesized by a one-step reaction of substituted phenyl diazonium salts [R{\textquoteright}(Ph)N2+Cl-] [a, R{\textquoteright}= 4-N(CH3)(2); b, R{\textquoteright} = 2OH; c, R{\textquoteright} = 2-CO2H; d, R{\textquoteright} = 4-NO2] with pyrrole under basic conditions. Asymmetric 2,5-bisazopyrroles 3(a-d) were synthesized by reacting substituted phenyl diazonium salts [R {\textquoteright}{\textquoteright}(Ph)N2+Cl-] (a, R {\textquoteright}{\textquoteright} = 4-OCH3; b, R {\textquoteright}{\textquoteright} = H; c, R {\textquoteright}{\textquoteright} = 4-Br; d, R {\textquoteright}{\textquoteright} = 4-NO2) with 2-(4-dimethylaminophenylazo)-1H-pyrrole (1a) under the same conditions. The reactions of 2a with boron trifluoride and iodomethane provided a BF2-azopyrrole complex of 1H-pyrrolo[2,1-c]-1,2,4,5-boratriazole (4) and 2,5-bisazo-1-methylpyrrole 5. X-ray crystallographic and spectral analysis of la, 2a, 2b, and 4 showed that la has three crystal forms: 1a(I), 1a(II), and 1a(III), the latter two bearing a bicyclic ring system formed via intermolecular hydrogen bonding. Complex 4 was found to be the most planar due to a rigid trans-azo configuration and has the longest N=N bond distances (1.322 and 1.300 angstrom) and wavelength of maximum absorption (754 nm). The N=N bond distances increase in the sequence of monoazopyrrole [1a(1): 1,253 angstrom], bisazopyrrole (2a: 1.283 angstrom), bisazopyrrole with intramolecular hydrogen bonding (2b: 1,293 and 1.293 angstrom), and the BF2-azopyrrole complex. Their maximum absorptions shift bathochromically in the sequence of monoazopyrrole (1a: 443 nm), bisazopyrroles [2(a-d), 3(a-d), 5: 486-615 nm), and the BF2-azopyrrole complex. These results are important for the design of near-infrared absorbing azo dyes and suggest an efficient path for the preparation of near-infrared absorbing azo dyes by effectively enhancing pi-electron delocalization.},
	keywords = {C-13 NMR, CI-DISPERSE-ORANGE-29, CRYSTAL-STRUCTURE, DERIVATIVES, DISAZO DYES, HETEROCYCLIC DIAZO COMPONENTS, INTRAMOLECULAR PROTON-TRANSFER, NONLINEARITIES, optical, PHOTODYNAMIC THERAPY, SOLID-STATE},
	isbn = {0022-3263},
	url = {<Go to ISI>://000268480300014},
	author = {Li, Y. and Patrick, B. O. and Dolphin, D.}
}
@article {2250,
	title = {Conformational flexibility of dipyrromethenes: supramolecular assemblies with hydroquinones},
	journal = {Crystengcomm},
	volume = {10},
	number = {8},
	year = {2008},
	note = {ISI Document Delivery No.: 329NUTimes Cited: 4Cited Reference Count: 10Shin, Ji-Young Patrick, Brian O. Dolphin, David},
	pages = {960-962},
	type = {Article},
	abstract = {The structure of a self-assembled system containing a protonated dipyrromethene with deprotonated/reduced dichlorodicyanoquinone (DDQ) was determined by X-ray diffraction analysis. The assembly exhibits a highly hydrogen-bonded structure, with an unusual asymmetric conformation for the dipyrromethene.},
	keywords = {CONDUCTING POLYMERS, N-CONFUSED PORPHYRINS, SOLID-STATE},
	isbn = {1466-8033},
	url = {<Go to ISI>://000257875100006},
	author = {Shin, J. Y. and Patrick, B. O. and Dolphin, D.}
}
@article {2249,
	title = {Self-assembly via intermolecular hydrogen-bonding between o-/m-/p-NH2 and BF2 groups on dipyrromethenes},
	journal = {Tetrahedron Letters},
	volume = {49},
	number = {38},
	year = {2008},
	note = {ISI Document Delivery No.: 349UTTimes Cited: 0Cited Reference Count: 17Shin, Ji-Young Patrick, Brian O. Dolphin, David},
	month = {Sep},
	pages = {5515-5518},
	type = {Article},
	abstract = {Boron difluoride dipyrromethenes bearing configurationally different amine groups on a meso-phenyl ring were prepared and crystallized. The ortho- and para-amino groups allow the phenyl group to inductively release greater electron density into the dipyrromethenes resulting in relatively strong intermolecular hydrogen-bonding with the terminal BF2 groups, whereas the meta-analog formed weaker hydrogen-bonds. The intensities of the H-1 NMR peaks in concentrated solutions all increased with F-decoupling. (C) 2008 Elsevier Ltd. All rights reserved.},
	keywords = {ANALOG, boron-dipyrromethene, CHEMISTRY, EFFICIENT, HYDROGEN-BOND, LIGANDS, MOLECULES, self-assembly, SOLID-STATE},
	isbn = {0040-4039},
	url = {<Go to ISI>://000259309500020},
	author = {Shin, J. Y. and Patrick, B. O. and Dolphin, D.}
}
@article {1637,
	title = {Engineering acyclic alkyl aryl ketones for enantioselective Norrish/Yang type II photochemistry in the crystalline state},
	journal = {Crystengcomm},
	volume = {8},
	number = {5},
	year = {2006},
	note = {ISI Document Delivery No.: 050IUTimes Cited: 8Cited Reference Count: 9},
	pages = {388-390},
	type = {Article},
	abstract = {While most alkyl aryl ketones fail to undergo the Norrish/Yang type II photoreaction in the solid state because they crystallize in conformations unfavorable for gamma-hydrogen atom abstraction, it was found with the aid of molecular mechanics that such is not the case for the 2-ethyl-1-arylbutan-1-one system; subsequent application of the solid state ionic chiral auxiliary method of asymmetric synthesis to derivatives of this ketone afforded the corresponding Yang cyclobutanol in enantiomeric excesses as high as 92\% at 91\% conversion.},
	keywords = {ASYMMETRIC INDUCTION, REACTIVITY, SOLID-STATE},
	isbn = {1466-8033},
	url = {<Go to ISI>://000238081700006},
	author = {Xia, W. J. and Yang, C. and Scheffer, J. R. and Patrick, B. O.}
}
@article {1610,
	title = {Monitoring reaction centers and molecules during an enantioselective photoreaction in a crystal},
	journal = {Crystengcomm},
	volume = {8},
	number = {8},
	year = {2006},
	note = {ISI Document Delivery No.: 071LZTimes Cited: 9Cited Reference Count: 19Turowska-Tyrk, Ilona Bakowicz, Julia Scheffer, John R. Xia, Wujiong},
	pages = {616-621},
	type = {Article},
	abstract = {The single crystal-to-single crystal retro-Claisen photorearrangement of the salt of 7-(4-carboxybenzoyl) norbornene with (S)-(2)-1-cyclohexylethylamine was studied. Although this reaction is an ionic chiral auxiliary-mediated asymmetric synthesis, which normally affords highly enantio-enriched products, the enantiomeric excess in this case is a relatively low 60\% (80\% of one enantiomer, 20\% of the other). X-ray structure analysis was used in order to describe changes in the reaction centers and the behavior of molecules during the photoreaction and to understand the formation of two enantiomers. It was discovered that the conformation of the reactant molecules changes during the photoreaction to one that enables the formation of the minor enantiomer. This was seen clearly at ca. 30\% reaction progress. The variations in the cell constants as a function of reaction progress are also presented. The structural changes taking place during the retro-Claisen photorearrangement are compared to the changes observed for other intra- and intermolecular photoreactions in crystals.},
	keywords = {2-BENZYL-5-BENZYLIDENECYCLOPENTANONE, ASYMMETRIC INDUCTION, PHOTODIMERIZATION, SOLID-STATE, STRUCTURAL TRANSFORMATIONS, Yang photocyclization},
	isbn = {1466-8033},
	url = {<Go to ISI>://000239605000007},
	author = {Turowska-Tyrk, I. and Bakowicz, J. and Scheffer, J. R. and Xia, W. J.}
}
@article {1398,
	title = {Optimization, standardization, and testing of a new NMR method for the determination of zeolite host-organic guest crystal structures},
	journal = {Journal of the American Chemical Society},
	volume = {128},
	number = {36},
	year = {2006},
	note = {ISI Document Delivery No.: 081BJTimes Cited: 15Cited Reference Count: 42Fyfe, Colin A. Brouwer, Darren H.},
	month = {Sep},
	pages = {11860-11871},
	type = {Article},
	abstract = {An optimized and automated protocol for determining the location of guest sorbate molecules in highly siliceous zeolites from Si-29 INADEQUATE and H-1/Si-29 cross polarization (CP) magic-angle spinning (MAS) NMR experiments is described. With the peaks in the Si-29 MAS NMR spectrum assigned to the unique Si sites in the zeolite framework by a 2D(29)Si INADEQUATE experiment, the location of the sorbate molecule is found by systematically searching for sorbate locations for which the measured rates of H-1/Si-29 cross polarization of the different Si sites correlate linearly with H-1/Si-29 second moments calculated from H-Si distances. Due to the H-1/Si-29 cross polarization being in the "slow CP regime" for many zeolite-sorbate complexes, it is proposed that the CP rate constants are best measured by H-1/Si-29 cross polarization drain experiments, if possible, to avoid complications that may arise from fast H-1 and Si-29 T-1 rho relaxations. An algorithm for determining the sorbate molecule location is described in detail. A number of ways to effectively summarize and display the large number of solutions which typically result from a prediction of the structure from the CP MAS NMR data are presented, including estimates of the errors involved in the structure determinations. As a working example throughout this paper, the structure of the low loaded rho-dichlorobenzene/ZSM-5 complex is determined under different conditions from solid-state H-1/Si-29 CP MAS NMR data, and the solutions are shown to be in excellent agreement with the known single-crystal X-ray diffraction structure. This structure determination approach is shown to be quite insensitive to the use of relative rate constants rather than absolute values, to the detailed structure of the zeolite framework, and relatively insensitive to temperature and motions.},
	keywords = {2ND MOMENT, CROSS-POLARIZATION, DETERMINATIONS, DISTANCE, H-ZSM-5, P-DICHLOROBENZENE, SINGLE-CRYSTAL, SOLID-STATE, SORBATE, SPINNING NMR, ZSM-5},
	isbn = {0002-7863},
	url = {<Go to ISI>://000240291900035},
	author = {Fyfe, C. A. and Brouwer, D. H.}
}
@article {1338,
	title = {Salts of the cobalt(I) complexes [Co(CO)(5)](+) and[Co(CO)(2)(NO)(2)](+) and the Lewis acid-base adduct [CO2(CO)(7)CO-B(CF3)(3)]},
	journal = {Chemistry-a European Journal},
	volume = {12},
	number = {32},
	year = {2006},
	note = {ISI Document Delivery No.: 110YZTimes Cited: 4Cited Reference Count: 60Bernhardt, Eduard Finze, Maik Willner, Helge Lehmann, Christian W. Aubke, Friedhelm},
	month = {Nov},
	pages = {8276-8283},
	type = {Article},
	abstract = {The reaction of [Co-2(CO)(8)] with (CF3)(3)BCO in hexane leads to the Lewis acid-base adduct [CO2(CO)(7)COB(CF3)(3)] in high yield. When the reaction is performed in anhydrous HF solution [Co(CO)(5)][(CF3)(3)BF] is isolated. The product contains the first example of a homoleptic metal pentacarbonyl cation with 18 valence electrons and a trigonal-bipyramidal structure. Treatment of [Co-2(CO)(8)] or [Co(CO)(3)NO] with NO+ salts of weakly coordinating anions results in mixed crystals containing the [Co(CO)(5)](+)/[Co(CO)(2)(NO)(2)](+) ions or pure novel [Co(CO)(2)(NO)(2)](+) salts, respectively. This is a promising route to other new metal carbonyl nitrosyl cations or even homoleptic metal nitrosyl cations. All compounds were characterized by vibrational spectroscopy and by single-crystal X-ray diffraction.},
	keywords = {ALUMINUM HALIDES, ANIONS, carbonyl ligands, cobalt, density, density functional calculations, DICOBALT OCTACARBONYL, EXCHANGE, LIGANDS, METAL-CARBONYL CATIONS, NITRIC-OXIDE, NITROSYL, SOLID-STATE, SPECTROSCOPIC PROPERTIES, vibrational spectroscopy, VIBRATIONAL-SPECTRA},
	isbn = {0947-6539},
	url = {<Go to ISI>://000242418600008},
	author = {Bernhardt, E. and Finze, M. and Willner, H. and Lehmann, C. W. and Aubke, F.}
}
@article {1304,
	title = {Asymmetric synthesis of dihydrofurans via a formal retro-Claisen photorearrangement},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {8},
	year = {2005},
	note = {ISI Document Delivery No.: 901URTimes Cited: 13Cited Reference Count: 36},
	month = {Mar},
	pages = {2725-2730},
	type = {Article},
	abstract = {Solution-phase irradiation of a series of syn-7-benzoylnorbornene derivatives is shown to lead to cis-fused dihydrofuran derivatives in low quantum but excellent chemical yields in what is formally a retro-Claisen rearrangement. In analogy to the well-known Paterno-Buchi reaction, the first step of the rearrangement is suggested to involve (n,pi*)(3)-mediated addition of the carbonyl oxygen to the norbornene double bond, producing a triplet 1,4-biradical. This intermediate, rather than closing to the oxetane, undergoes cleavage accompanied by intersystem crossing to form the dihydrofuran. To determine whether the retro-Claisen photorearrangement could be carried out enantioselectively, the 7-benzoylnorbornene reactant was equipped with a para-carboxylic acid substituent to which a series of optically pure amines was attached ionically via salt bridges. Irradiation of these salts in the crystalline state followed by diazomethane workup (the solid-state ionic chiral auxiliary method) was shown to afford the corresponding dihydrofuran in optical yields as high as 93\% at 95\% conversion. X-ray crystallography revealed that the enantioselectivity arises from crystallization of the reactant in a conformation in which the carbonyl oxygen is more favorably oriented for bond formation to one end of the norbornene double bond than the other, thus leading to a predominance of a single enantiomer.},
	keywords = {FURANS, GENERAL-APPROACH, INDUCTION, PHENYL KETONES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, REARRANGEMENT, SOLID-STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000227308100059},
	author = {Xia, W. J. and Yang, C. and Patrick, B. O. and Scheffer, J. R. and Scott, C.}
}
@article {951,
	title = {Synthesis and insulinomimetic activities of novel mono- and tetranuclear oxovanadium(IV) complexes with 3-hydroxypyridine-2-carboxylic acid},
	journal = {Journal of Inorganic Biochemistry},
	volume = {98},
	number = {1},
	year = {2004},
	note = {ISI Document Delivery No.: 760DETimes Cited: 24Cited Reference Count: 21},
	month = {Jan},
	pages = {105-112},
	type = {Article},
	abstract = {Two chargeless VO(IV) complexes with 3-hydroxypyridine-2-carboxylic acid (H(2)hpic), [VO(Hhpic-O,O)(Hhpic-O,N)(H2O)(.)3H(2)O (1) and the cyclic tetramer [(VO)4(mu-(hpic-O,O,N))(4)(H2O)(4)](.)8H(2)O (2), have been synthesized and characterized by elemental analysis, mass, infrared, electronic absorption, electron spin resonance (ESR) spectroscopies, and X-ray crystallography. Their coordination structures are similar to each other (and 1 is readily transformed into 2), but are quite different from that of bis(pyridine-2-carboxylato)oxovanadium(IV). The magnetic susceptibility of 2 indicates the presence of a weak ferromagnetic intramolecular interaction between the V atoms at low temperature, in addition to a weak antiferromagnetic intermolecular interaction. The ESR signal of 2 was broad, while I showed an eight-line hyperfine splitting pattern due to coupling of the impaired electron with the V-51 nucleus (I = 7/2). The ESR spectrum and cyclic voltammogram of 2 clearly show that the cyclic tetramer remains intact in solution. The insulinomimetic activity of 1 and 2 was evaluated by means of in vitro measurements of the inhibition of free fatty acid release from epinephrine-treated isolated rat adipocytes. While I exerted higher insulinomimetic activity than VOSO4, the activity of 2 was significantly lower than that of VOSO4. Hence 2 appears to retain its cyclic structure during the in vitro test. These results indicate that the rational ligand design for VO complexes might be a promising approach to obtain superior insulinomimetic activity. (C) 2003 Elsevier Inc. All rights reserved.},
	keywords = {BLOOD-GLUCOSE, cyclic tetranuclear complex, INDUCED DIABETIC RATS, insulinomimetic activity, oxovanadium, SOLID-STATE, VANADIUM(IV), VANADYL COMPLEX},
	isbn = {0162-0134},
	url = {<Go to ISI>://000187795700014},
	author = {Nakai, M. and Obata, M. and Sekiguchi, F. and Kato, M. and Shiro, M. and Ichimura, A. and Kinoshita, I. and Mikuriya, M. and Inohara, T. and Kawabe, K. and Sakurai, H. and Orvig, Chris and Yano, S.}
}
@article {710,
	title = {Preorganization of achiral molecules for asymmetric synthesis through crystallization-induced immobilization in homochiral conformations},
	journal = {Angewandte Chemie-International Edition},
	volume = {42},
	number = {32},
	year = {2003},
	note = {ISI Document Delivery No.: 716PRTimes Cited: 19Cited Reference Count: 24},
	pages = {3775-3777},
	type = {Article},
	keywords = {asymmetric synthesis, CRYSTAL, crystal engineering, GEOMETRIC REQUIREMENTS, II, INDUCTION, KETONES, PHOTOCHEMICAL-REACTIONS, PHOTOCHEMISTRY, PHOTOCYCLIZATION, reaction, REACTIONS, REACTIVITY, SOLID-STATE, topochemistry},
	isbn = {1433-7851},
	url = {<Go to ISI>://000185038000009},
	author = {Patrick, B. O. and Scheffer, J. R. and Scott, C.}
}
@article {699,
	title = {Thermal activation of hydrocarbon C-H bonds initiated by a tungsten allyl complex},
	journal = {Journal of the American Chemical Society},
	volume = {125},
	number = {49},
	year = {2003},
	note = {ISI Document Delivery No.: 750QETimes Cited: 12Cited Reference Count: 62},
	month = {Dec},
	pages = {15210-15223},
	type = {Article},
	abstract = {Gentle thermolysis of the allyl complex, (CpW)-W-*(NO)(CH2CMe3)(eta(3)-H2CCHCMe2) (1), at 50 degreesC in neat hydrocarbon solutions results in the loss of neopentane and the generation of transient intermediates that subsequently activate solvent C-H bonds. Thus, thermal reactions of 1 with tetramethylsilane, mesitylene, and benzene effect single C-H activations and lead to the exclusive formation of (CpW)-W-*(NO)(CH2SiMe3)(eta(3)-H2CCHCMe2) (2), (CpW)-W-*(NO)(CH2C6H3-3,5-Me-2)(eta(3)-H2CCHCMe2) (3), and (CpW)-W-*(NO)(C6H5)(eta(3)-H2CCHCMe2) (4), respectively. The products of reactions of 1 with other methyl-substituted arenes indicate an inherent preference of the system for the activation of stronger arene sp(2) C-H bonds. For example, C-H bond activation of p-xylene leads to the formation of (CpW)-W-*(NO)(CH2C6H4-4-Me)(eta(3)-H2CCHCMe2) (5) (26\%) and (CpW)-W-*(NO)(C6H3-2,5-Me-2)(eta(3)-H2CCHCMe2) (6) (74\%). Mechanistic and labeling studies indicate that the transient C-H-activating intermediates are the allene complex, (CpW)-W-*(NO)(eta(2)-H2C=C=CMe2) (A), and the eta(2)-diene complex, (CpW)-W-*(NO)(eta(2)-H2C=CHC(Me)=CH2) (B). Intermediates A and B react with cyclohexene to form (CpW)-W-*(NO)(eta(3)-CH2C(2-cyclohexenyl)CMe2)(H) (18) and (CpW)-W-*(NO)(eta(3)-CH2CHC)(Me)CH2CbetaH(C4H8)CalphaH (19), respectively, and intermediate A can be isolated as its PMe3 adduct, (CpW)-W-*(NO)(PMe3)(eta(2)-H2C=C=CMe2) (20). Interestingly, thermal reaction of 1 with 2,3-dimethylbut-2-ene results in the formation of a species that undergoes eta(3) {\textendash}> eta(1) isomerization of the dimethylallyl ligand following the initial C-H bond-activating step to yield (CpW)-W-*(NO)(eta(3)-CMe2CMeCH2)(eta(1)-CH2CHCMe2) (21). Thermolyses of 1 in alkane solvents afford allyl hydride complexes resulting from three successive C-H bond-activation reactions. For instance, 1 in cyclohexane converts to (CpW)-W-*(NO)(eta(3)-C6H9)(H) (22) with dimethylpropylcyclohexane being formed as a byproduct, and in methylcyclohexane it forms the two isomeric complexes, (CpW)-W-*(NO)(eta(3)-C7H11)(H) (23a,b). All new complexes have been characterized by conventional spectroscopic methods, and the solid-state molecular structures of 2, 3, 4, 18, 19, 20, and 21 have been established by X-ray crystallographic analyses.},
	keywords = {ALKYLIDENE COMPLEXES, ALLENE, CHEMICAL-PROPERTIES, COMPLEXES, CRYSTAL-STRUCTURE, ETA-3-ALLYL COMPLEXES, MOLECULAR-STRUCTURE, ORGANOMETALLIC NITROSYL CHEMISTRY, SOLID-STATE, STRUCTURAL CHARACTERIZATION, TRANSITION-METAL COMPLEXES},
	isbn = {0002-7863},
	url = {<Go to ISI>://000187007400050},
	author = {Ng, S. H. K. and Adams, C. S. and Hayton, T. W. and Legzdins,Peter and Patrick, B. O.}
}
@article {592,
	title = {Thermal and photochemical transformation of conformational chirality into configurational chirality in the crystalline state},
	journal = {Journal of the American Chemical Society},
	volume = {125},
	number = {14},
	year = {2003},
	note = {ISI Document Delivery No.: 663JYTimes Cited: 15Cited Reference Count: 12},
	month = {Apr},
	pages = {4040-4041},
	type = {Article},
	keywords = {ASYMMETRIC INDUCTION, SOLID-STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000182003500017},
	author = {Chong, K. C. W. and Scheffer, J. R.}
}
@article {565,
	title = {1-Methyl-5,6-diphenylpyrazine-2(1H)-thione},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {58},
	year = {2002},
	note = {ISI Document Delivery No.: 536YDTimes Cited: 2Cited Reference Count: 11Part 4},
	month = {Apr},
	pages = {O220-O222},
	type = {Article},
	abstract = {The title compound, C17H14N2S, crystallizes in a triclinic unit cell, with two crystallographically independent molecules in the asymmetric unit. The two independent molecules pack in the same sense and form segregated layers along the c axis. The crystal is light-stable and no dimers are formed under irradiation. The intermolecular distances between the potential reactive centers (the C-3 and C-5 ring positions) are 4.093 (4) and 5.643 (4) Angstrom for molecule A, and 4.081 (4) and 5.614 (4) Angstrom for molecule B.},
	keywords = {DIMERIZATION, SOLID-STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://000174728700038},
	author = {Zolotoy, A. B. and Botoshansky, M. and Kaftory, M. and Scheffer, J. R. and Yang, J.}
}
@article {458,
	title = {Enhanced enantio- and diastereoselectivity via confinement and cation binding: Yang photocyclization of 2-benzoyladamantane derivatives within zeolites},
	journal = {Journal of Organic Chemistry},
	volume = {67},
	number = {24},
	year = {2002},
	note = {ISI Document Delivery No.: 620AATimes Cited: 5Cited Reference Count: 60},
	month = {Nov},
	pages = {8339-8350},
	type = {Article},
	abstract = {Irradiation of 2-benzoyladamantane derivatives in zeolites yields the endo-cyclobutanols as the only photoproduct via a gamma-hydrogen abstraction process. The cyclobutanols readily undergo retro-aldol reaction to give delta-ketoesters. The enantiomeric excess (ee) in the endo-cyclobutanols is measured by monitoring the ee in the ketoesters. Whereas in solution the ee in the product ketoester is zero, within achiral NaY zeolite, in the presence of a chiral inductor such as pseudoephedrine, ee{\textquoteright}s up to 28\% have been obtained. The influence of zeolite on several chiral esters of 2-benzoyladamantane-2-carboxylic acids has also been examined. Whereas in solution the diastereomeric excess is <15\%, in zeolite the delta-ketoesters are obtained in 79\% de (best examples). Ab initio computations suggest that enhancement of chiral induction within zeolites is likely to be due to cation complexation with the reactant ketone. Alkali ion-organic interaction, a powerful tool, is waiting to be fully exploited in photochemical and thermal reactions. In this context zeolites could be a useful medium as one could view them as a reservoir of "naked" alkali ions that are only partially coordinated to the zeolite walls.},
	keywords = {ABSOLUTE ASYMMETRIC-SYNTHESIS, ACID-DERIVATIVES, CATALYSTS, COMPLEXES, EPOXIDATION, INDUCTION, PHOTOREACTIONS, SOLID-STATE, STATE ORGANIC-PHOTOCHEMISTRY, TROPOLONE ETHER},
	isbn = {0022-3263},
	url = {<Go to ISI>://000179509400006},
	author = {Natarajan, A. and Joy, A. and Kaanumalle, L. S. and Scheffer, J. R. and Ramamurthy, V.}
}
@article {532,
	title = {Enhanced regioselectivity of Yang photocyclization in the crystalline state},
	journal = {Organic Letters},
	volume = {4},
	number = {7},
	year = {2002},
	note = {ISI Document Delivery No.: 536BDTimes Cited: 9Cited Reference Count: 13},
	month = {Apr},
	pages = {1071-1074},
	type = {Article},
	abstract = {[GRAPHICS] In contrast to the solution state, where Yang photocyclization of ketones of general structure 1 leads to equal amounts of cyclobutanols 2 and 3 (by abstraction of H-A and H-B, respectively), irradiation in the crystalline state is much more regioselective, favoring either 2 or 3 depending on the nature of the substituent X. X-ray crystallography and molecular mechanics calculations reveal the source of this remarkable solid-state regioselectivity.},
	keywords = {ABSTRACTION, GAMMA, GEOMETRIC REQUIREMENTS, II REACTION, PHOTOCHEMISTRY, SOLID-STATE},
	isbn = {1523-7060},
	url = {<Go to ISI>://000174680100006},
	author = {Vishnumurthy, K. and Cheung, E. and Scheffer, J. R. and Scott, C.}
}
@article {5101,
	title = {An unexpected Paterno-Buchi reaction in the crystalline state},
	journal = {Organic Letters},
	volume = {3},
	number = {21},
	year = {2001},
	note = {ISI Document Delivery No.: 484UMTimes Cited: 6Cited Reference Count: 43},
	month = {Oct},
	pages = {3361-3364},
	type = {Article},
	abstract = {[GRAPHICS] The solution and solid-state photochemistry of a series of aryl 1-phenylcyclopentyl ketones (1) was investigated. While typical Norrish type I products were formed in solution, irradiation of crystals of I afforded the novel oxetanes 3 and 4 regiospecifically. The formation of the oxetanes is believed to occur through Norrish type I cleavage and hydrogen abstraction, producing an alkene and an aldehyde, followed by a Paternb-BUchi reaction within the crystal lattice cage.},
	keywords = {ASYMMETRIC INDUCTION, ORGANIC-PHOTOCHEMISTRY, PHOTOCYCLOADDITION, SALTS, SOLID-STATE, YANG PHOTOCYCLIZATION REACTION},
	isbn = {1523-7060},
	url = {<Go to ISI>://000171708000034},
	author = {Kang, T. and Scheffer, J. R.}
}
@article {4923,
	title = {Enantioselective photoelectrocyclization of a tropolone derivative in the crystalline state},
	journal = {Journal of Physical Organic Chemistry},
	volume = {13},
	number = {9},
	year = {2000},
	note = {ISI Document Delivery No.: 349GNTimes Cited: 5Cited Reference Count: 15},
	month = {Sep},
	pages = {531-538},
	type = {Article},
	abstract = {Achiral tropolone ethers are well known to undergo photochemically induced disrotatory electrocyclic ring closure in solution to form racemic bicyclo[3.2.0]hepta-3,6-dien-2-one derivatives. The present paper reports successful efforts to carry out this transformation enantioselectively through the use of the solid-state ionic chiral auxiliary method. in this method, the reactant, an achiral tropolone ether, is equipped with a carboxylic acid group to which an optically pure amine can be attached by salt formation. Salts such as these are required to crystallize in chiral space groups, which provide asymmetric reaction cavities capable of differentiating enantiomeric transition states. Irradiation of these materials in the solid state leads to enantiomerically enriched products in moderate to high enantiomeric excess depending on the amine employed. Of the amines studied, the best results were obtained with 1-phenylethylamine and 1-amido-2-indanol, which gave enantiomeric excesses in the 60-80\% range depending on the extent of conversion. Because the tropolone ring is planar, it is suggested that the stereochemical outcome of the electrocyclization in the solid state is governed by environmental crystal lattice effects rather than by the initial conformation of the reactant. Copyright (C) 2000 John Wiley \& Sons, Ltd.},
	keywords = {ALKYL ETHERS, ASYMMETRIC INDUCTION, crystalline tropolones, electrocyclic ring closure, enantioselective photoelectrocyclization, PHOTOCHEMISTRY, PHOTOREACTIONS, SOLID-STATE, YANG PHOTOCYCLIZATION REACTION},
	isbn = {0894-3230},
	url = {<Go to ISI>://000089037500007},
	author = {Scheffer, J. R. and Wang, L. T.}
}
@article {4840,
	title = {The influence of chiral auxiliaries is enhanced within zeolites},
	journal = {Tetrahedron Letters},
	volume = {41},
	number = {43},
	year = {2000},
	note = {ISI Document Delivery No.: 368NKTimes Cited: 18Cited Reference Count: 20},
	month = {Oct},
	pages = {8231-8235},
	type = {Article},
	abstract = {Zeolites significantly enhance the influence of chiral auxiliaries during photochemical reactions. The generality of this phenomenon has been tested with three independent examples. Chiral auxiliaries that lead to 1:1 mixtures of diastereomers in solution give products in up to 80\% diastereomeric excess in the presence of faujasite type zeolites. (C) 2000 Elsevier Science Ltd. All rights reserved.},
	keywords = {ASYMMETRIC PHOTOCHEMICAL-REACTIONS, ESTERS, INDUCTION, MODEL, SOLID-STATE},
	isbn = {0040-4039},
	url = {<Go to ISI>://000090123600010},
	author = {Jayaraman, S. and Uppili, S. and Natarajan, A. and Joy, A. and Chong, K. C. W. and Netherton, M. R. and Zenova, A. and Scheffer, J. R. and Ramamurthy, V.}
}
@article {4844,
	title = {Photochemistry of a tropolone ether and 2,2-dimethyl-1-(2H)-naphthalenones within a zeolite: Enhanced diastereoselectivity via confinement},
	journal = {Journal of the American Chemical Society},
	volume = {122},
	number = {4},
	year = {2000},
	note = {ISI Document Delivery No.: 281MUTimes Cited: 56Cited Reference Count: 27},
	month = {Feb},
	pages = {728-729},
	type = {Article},
	keywords = {INDUCTION, PHOTOREACTIONS, SOLID-STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000085165200030},
	author = {Joy, A. and Uppili, S. and Netherton, M. R. and Scheffer, J. R. and Ramamurthy, V.}
}
@article {4549,
	title = {Characterization of Na5P3O10 polymorphs by Na-23 MAS, Na-23 MQMAS, and P-31 MAS NMR spectroscopy},
	journal = {Inorganic Chemistry},
	volume = {38},
	number = {1},
	year = {1999},
	note = {ISI Document Delivery No.: 157MUTimes Cited: 20Cited Reference Count: 42},
	month = {Jan},
	pages = {84-92},
	type = {Article},
	abstract = {The two anhydrous polymorphs of Na5P3O10 have been characterized by Na-23 and P-31 MAS NMR spectroscopy, The Na-23 multiple-quantum (MQ) MAS NMR spectrum of the low-temperature form (phase II) displays three resonances for which the quadrupole coupling parameters and isotropic chemical shifts have been accurately determined from the MAS NMR spectra of the central transition. Thereby, discrepancies between recently reported Na-23 MQMAS spectra of this phase and the crystal structure have been clarified. The Na-23 resonances observed for the low-temperature form are assigned to the crystallographically nonequivalent Na sites in the crystal structure using point-monopole calculations of the electric-field gradient tensors. Three Na-23 resonances have also been observed for the high-temperature form (phase I), with two signals having very similar quadrupolar couplings and isotropic chemical shifts indicating similar coordination environments for the corresponding Na sites, in disagreement with the reported single-crystal structure. Point-monopole calculations of the electric-field gradient tensors based on the crystal structure fail to reproduce the experimental values. The P-31 chemical shielding anisotropies, obtained from P-31 MAS NMR spectra, show that the terminal P atoms of the P3O105- ions have a negative shielding anisotropy parameter (delta(sigma) = delta(iso) - delta(33)) in agreement with similar observations reported for diphosphates. This characteristic feature has been used in the assignment of the three P-31 resonances observed for the hexahydrate Na5P3O10. 6H(2)O.},
	keywords = {2-SPIN SYSTEMS, ANGLE-SPINNING NMR, CHEMICAL SHIELDING, CONDENSED PHOSPHATES, DIPOLAR, NUCLEAR-MAGNETIC-RESONANCE, QUADRUPOLAR NUCLEI, SODIUM TRIPHOSPHATE, SOLID-STATE, SPECTRA, TENSORS},
	isbn = {0020-1669},
	url = {<Go to ISI>://000078066900013},
	author = {Fyfe, C. A. and Altenschildesche, H. M. Z. and Skibsted, J.}
}
@article {4505,
	title = {An ionic chiral auxiliary-induced regioselective and enantioselective Yang photocyclization reaction in the crystalline state},
	journal = {Tetrahedron Letters},
	volume = {40},
	number = {50},
	year = {1999},
	note = {ISI Document Delivery No.: 258FJTimes Cited: 16Cited Reference Count: 19},
	month = {Dec},
	pages = {8729-8732},
	type = {Article},
	abstract = {cis-9-Decalyl aryl ketones undergo Yang photocyclization in solution to afford an approximately 1:1 mixture of two regioisomeric racemic cyclobutanols. In contrast, irradiation in the crystalline state in the presence of various ionic chiral auxiliaries leads to a single cyclobutanol in >98\% enantiomeric excess. X-Ray crystallography reveals the source of the regio-, diastereo- and enantioselectivity. (C) 1999 Elsevier Science Ltd. All rights reserved.},
	keywords = {ASYMMETRIC INDUCTION, CARBOXYLATE, KETONES, ORGANIC-PHOTOCHEMISTRY, PHOTOCHEMISTRY, SOLID-STATE, Yang photocyclization},
	isbn = {0040-4039},
	url = {<Go to ISI>://000083827200003},
	author = {Cheung, E. and Kang, T. and Raymond, J. R. and Scheffer, J. R. and Trotter, J.}
}
@article {4505,
	title = {An ionic chiral auxiliary-induced regioselective and enantioselective Yang photocyclization reaction in the crystalline state},
	journal = {Tetrahedron Letters},
	volume = {40},
	number = {50},
	year = {1999},
	note = {ISI Document Delivery No.: 258FJTimes Cited: 16Cited Reference Count: 19},
	month = {Dec},
	pages = {8729-8732},
	type = {Article},
	abstract = {cis-9-Decalyl aryl ketones undergo Yang photocyclization in solution to afford an approximately 1:1 mixture of two regioisomeric racemic cyclobutanols. In contrast, irradiation in the crystalline state in the presence of various ionic chiral auxiliaries leads to a single cyclobutanol in >98\% enantiomeric excess. X-Ray crystallography reveals the source of the regio-, diastereo- and enantioselectivity. (C) 1999 Elsevier Science Ltd. All rights reserved.},
	keywords = {ASYMMETRIC INDUCTION, CARBOXYLATE, KETONES, ORGANIC-PHOTOCHEMISTRY, PHOTOCHEMISTRY, SOLID-STATE, Yang photocyclization},
	isbn = {0040-4039},
	url = {<Go to ISI>://000083827200003},
	author = {Cheung, E. and Kang, T. and Raymond, J. R. and Scheffer, J. R. and Trotter, J.}
}
@article {4573,
	title = {The Norrish type II reaction in the crystalline state: Toward a better understanding of the geometric requirements for gamma-hydrogen atom abstraction},
	journal = {Tetrahedron},
	volume = {55},
	number = {4},
	year = {1999},
	note = {ISI Document Delivery No.: 159BRTimes Cited: 69Cited Reference Count: 58},
	month = {Jan},
	pages = {885-907},
	type = {Article},
	abstract = {By correlating the success or failure of the Norrish type II reaction for a series of compounds in the crystalline state with geometric data derived from X-ray crystallography (the so-called Crystal Structure-Solid State Reactivity Method), the distance and angular requirements for photochemical gamma-hydrogen atom abstraction have been established. These studies indicate that abstractions are preferred when the C=O ... H-gamma, distance is close to the sum of the van der Waals radii of hydrogen and oxygen (2.72 Angstrom), and that the gamma-hydrogen atom can deviate by as much as 50-60 degrees from the plane containing the oxygen n-orbital responsible for abstraction. Because molecular conformations and interatomic distances and angles can be calculated readily by using empirical force field methods, such data permit predictions to be made concerning the outcome of hypothetical Norrish type II processes. (C) 1999 Elsevier Science Ltd. All rights reserved.},
	keywords = {ABSOLUTE ASYMMETRIC-SYNTHESIS, CONFORMATIONAL CONTROL, ENVIRONMENT, KETONES, METHODOLOGY, MOLECULES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, SOLID-STATE, SPECTRA},
	isbn = {0040-4020},
	url = {<Go to ISI>://000078152400001},
	author = {Ihmels, H. and Scheffer, J. R.}
}
@article {4344,
	title = {alpha-naphthyl phenyl pinacols},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {54},
	year = {1998},
	note = {ISI Document Delivery No.: 116CDTimes Cited: 2Cited Reference Count: 16Part 8},
	month = {Aug},
	pages = {1148-1151},
	type = {Article},
	abstract = {Treatment of alpha-naphthyl phenyl ketone with Zn/acetic acid gives racemic alpha-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C34H26O2, but reaction with Mg/MgI2 gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo[7.4.0.0(2,6)]trideca-7,9,11,13 -tetraen-3-ol, C34H26O2 The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures, the OH groups are involved in only weak intermolecular interactions.},
	keywords = {BOND LENGTH, REACTIVITY, REARRANGEMENT, SOLID-STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://000075704700047},
	author = {Mak, T. C. W. and Patrick, B. O. and Rettig, S. J. and Scheffer, J. R. and Trotter, J. and Ukpabi, P. and Wu, B. M. and Yee, V. C.}
}
@article {4344,
	title = {alpha-naphthyl phenyl pinacols},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {54},
	year = {1998},
	note = {ISI Document Delivery No.: 116CDTimes Cited: 2Cited Reference Count: 16Part 8},
	month = {Aug},
	pages = {1148-1151},
	type = {Article},
	abstract = {Treatment of alpha-naphthyl phenyl ketone with Zn/acetic acid gives racemic alpha-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C34H26O2, but reaction with Mg/MgI2 gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo[7.4.0.0(2,6)]trideca-7,9,11,13 -tetraen-3-ol, C34H26O2 The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures, the OH groups are involved in only weak intermolecular interactions.},
	keywords = {BOND LENGTH, REACTIVITY, REARRANGEMENT, SOLID-STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://000075704700047},
	author = {Mak, T. C. W. and Patrick, B. O. and Rettig, S. J. and Scheffer, J. R. and Trotter, J. and Ukpabi, P. and Wu, B. M. and Yee, V. C.}
}
@article {4387,
	title = {The reactivity of five-coordinate Ru(II)(1,4-bis(diphenylphosphino)butane) complexes with the N-donor ligands: ammonia, pyridine, 4-substituted pyridines, 2,2{\textquoteright}-bipyridine, bis(o-pyridyl)amine, 1,10-phenanthroline, 4,7-diphenylphenanthroline and ethylene},
	journal = {Inorganica Chimica Acta},
	volume = {267},
	number = {2},
	year = {1998},
	note = {ISI Document Delivery No.: YK955Times Cited: 48Cited Reference Count: 47},
	month = {Jan},
	pages = {209-221},
	type = {Article},
	abstract = {{A series of Ru(II) (1,4-bis(diphenylphosphino)butane) (L)(2) complexes was synthesized from [RuCl2(dppb)](2)(mu-dppb) or RuCl2(dppb)-(PPh3); dppb=Ph2P(CH2)(4)PPh2},
	keywords = {1, 4-BIS(DIPHENYLPHOSPHINO)BUTANE, amine-phosphine complexes, crystal structures, CRYSTAL-STRUCTURE, HYDROGENATION, IMINE, PHOSPHINE COMPLEXES, RUTHENIUM(II), RUTHENIUM(II) COMPLEXES, SOLID-STATE, X-RAY},
	isbn = {0020-1693},
	url = {<Go to ISI>://A1998YK95500005},
	author = {Queiroz, S. L. and Batista, A. A. and Oliva, G. and Gambardella, Mtdp and Santos, R. H. A. and Macfarlane, K. S. and Rettig, S. J. and James, Brian R.}
}
@article {4018,
	title = {N,N-diethyl-N{\textquoteright}-methyl-4b,8b,8c,8d-tetrahydrodibenzo[a,f]cyclopropa[cd]pe ntalene-8b,8c-dicarboxamide},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {53},
	year = {1997},
	note = {ISI Document Delivery No.: XZ627Times Cited: 0Cited Reference Count: 9Part 9},
	month = {Sep},
	pages = {1263-1265},
	type = {Article},
	abstract = {The title compound, C23H24N2O2, is a product of photolysis of an unsymmetrical dibenzobarrelene diamide and has a dibenzosemibullvalene structure with normal molecular geometry and dimensions. Molecules are linked by one N-H ... O hydrogen bond.},
	keywords = {CRYSTAL-STRUCTURES, SOLID-STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://A1997XZ62700044},
	author = {Jones, R. and Rattray, A. G. M. and Scheffer, J. R. and Trotter, J.}
}
@article {4018,
	title = {N,N-diethyl-N{\textquoteright}-methyl-4b,8b,8c,8d-tetrahydrodibenzo[a,f]cyclopropa[cd]pe ntalene-8b,8c-dicarboxamide},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {53},
	year = {1997},
	note = {ISI Document Delivery No.: XZ627Times Cited: 0Cited Reference Count: 9Part 9},
	month = {Sep},
	pages = {1263-1265},
	type = {Article},
	abstract = {The title compound, C23H24N2O2, is a product of photolysis of an unsymmetrical dibenzobarrelene diamide and has a dibenzosemibullvalene structure with normal molecular geometry and dimensions. Molecules are linked by one N-H ... O hydrogen bond.},
	keywords = {CRYSTAL-STRUCTURES, SOLID-STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://A1997XZ62700044},
	author = {Jones, R. and Rattray, A. G. M. and Scheffer, J. R. and Trotter, J.}
}
@article {2838,
	title = {NOVEL PHOTOCHEMISTRY OF A STERICALLY CROWDED MONOBENZOBARRELENE DERIVATIVE},
	journal = {Tetrahedron Letters},
	volume = {34},
	number = {1},
	year = {1993},
	note = {ISI Document Delivery No.: KE371Times Cited: 6Cited Reference Count: 12},
	month = {Jan},
	pages = {31-34},
	type = {Article},
	abstract = {The solution phase photochemistry of the sterically congested tetramethylated benzobarrelene derivative 2b differs completely from that of its non-methylated counterpart, 2a. Based on molecular mechanics calculations, the factor that is suggested to be responsible for this difference is relief of the unfavorable methyl-methyl interactions present in 2b.},
	keywords = {3-DICARBOXYLATE, 4-DIHYDRO-1, 4-ETHENONAPHTHALENE-2, DIMETHYL 1, SOLID-STATE, SUBSTITUTED DIBENZOBARRELENE},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1993KE37100005},
	author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yap, M.}
}
@article {2838,
	title = {NOVEL PHOTOCHEMISTRY OF A STERICALLY CROWDED MONOBENZOBARRELENE DERIVATIVE},
	journal = {Tetrahedron Letters},
	volume = {34},
	number = {1},
	year = {1993},
	note = {ISI Document Delivery No.: KE371Times Cited: 6Cited Reference Count: 12},
	month = {Jan},
	pages = {31-34},
	type = {Article},
	abstract = {The solution phase photochemistry of the sterically congested tetramethylated benzobarrelene derivative 2b differs completely from that of its non-methylated counterpart, 2a. Based on molecular mechanics calculations, the factor that is suggested to be responsible for this difference is relief of the unfavorable methyl-methyl interactions present in 2b.},
	keywords = {3-DICARBOXYLATE, 4-DIHYDRO-1, 4-ETHENONAPHTHALENE-2, DIMETHYL 1, SOLID-STATE, SUBSTITUTED DIBENZOBARRELENE},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1993KE37100005},
	author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yap, M.}
}
@article {7244,
	title = {PROTOTROPIC CONTROL OF ORGANIC-PHOTOCHEMISTRY - HYDROGEN-BONDING EFFECTS ON THE DI-PI-METHANE PHOTOREARRANGEMENT},
	journal = {Journal of Organic Chemistry},
	volume = {57},
	number = {1},
	year = {1992},
	note = {ISI Document Delivery No.: GY184Times Cited: 6Cited Reference Count: 54},
	month = {Jan},
	pages = {241-247},
	type = {Article},
	abstract = {The IR and UV spectra as well as the photochemistry of the isopropyl monoester of dibenzobarrelene dicarboxylic acid 2 were analyzed in detail in several media. A correlation was found between the photochemical results and the spectroscopically detected hydrogen-bonded structures of 2. An equilibrium between dimeric (2-HD) and intramolecularly hydrogen bonded (2-HI) structures was detected by IR spectroscopy in nonpolar solvents having weak hydrogen-bond-accepting capabilities. The ratio of the two regioisomeric dibenzosemibullvalene products 3 and 4 formed in the di-pi-methane photorearrangement of 2 was found to correlate with such an equilibrium, and it was concluded that intramolecular (2-HI) and dimeric (2-HD) hydrogen-bonded structures display significantly different photochemical reactivity. The infrared spectra and the photoproduct ratio in polar solvents possessing hydrogen-bond-accepting capabilities (e.g., acetonitrile), on the other hand, turned out to be concentration independent. High regioselectivity was found in the solid state where the dimer 2-HD is the only species, leading to 4 as the major product. In contrast, 3 was obtained preferentially in aqueous sodium bicarbonate solutions where 2 exists as the carboxylate anion. Supporting evidence regarding the different hydrogen bonding arrangements in 2 was found in the solvent effects on its UV spectra.},
	keywords = {ABSORPTION, DIBENZOBARRELENES, EXCITED-STATE, LASER EXCITATION FLUORESCENCE, METHYL SALICYLATE, ORTHO-HYDROXYBENZALDEHYDE, PHOTOISOMERIZATION, REARRANGEMENTS, SOLID-STATE, STATE PROTON-TRANSFER},
	isbn = {0022-3263},
	url = {<Go to ISI>://A1992GY18400043},
	author = {Garciagaribay, M. A. and Scheffer, J. R. and Watson, D. G.}
}
