@article {29816,
	title = {Computational study of the structures and photoelectron spectra of gas-phase nitrosamines: Dimethylnitrosamine, N-nitrosopyrrolidine and 1-nitrosoaziridine},
	journal = {Journal of Electron Spectroscopy and Related Phenomena},
	volume = {232},
	year = {2019},
	pages = {35 - 39},
	abstract = {<p>The structures of three nitrosamines in gas phase are optimized with various levels of theory available in the Gaussian program. For dimethylnitrosamine and N-nitrosopyrrolidine, the reported rotational constants from microwave spectra let us select the best optimized geometry. For 1-nitrosoaziridine, however, we decide to choose the geometry optimized by CCSD/cc-pVTZ method. At these geometries, the photoelectron spectra are calculated with established methods using the Amsterdam Density Functional program. The calculated ionization energies of valence electrons agree well with available experimental data and provide values for the missing photoelectron data. On the other hand, the computed core-electron binding energies of dimethylnitrosamine agree well with the values from 1975 X-ray solid-state photoelectron spectra after adding the work function. The predicted values for N-nitrosopyrrolidine and 1-nitrosoaziridine must wait for experiments for confirmation.</p>},
	keywords = {core-electron binding energies, ESCA, Nitrosamines, photoelectron spectra, structures, Vertical ionization energies},
	issn = {0368-2048},
	doi = {https://doi.org/10.1016/j.elspec.2018.12.001},
	url = {http://www.sciencedirect.com/science/article/pii/S0368204818302275},
	author = {Delano P. Chong}
}
@article {1115,
	title = {Solid state NMR method for the determination of 3D zeolite framework/sorbate structures: H-1/Si-29 CP MAS NMR study of the high-loaded form of p-xylene in ZSM-5 and determination of the unknown structure of the low-loaded form},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {20},
	year = {2005},
	note = {ISI Document Delivery No.: 928AXTimes Cited: 22Cited Reference Count: 57},
	month = {May},
	pages = {7543-7558},
	type = {Article},
	abstract = {A general protocol is described for structure determinations of organic sorbate-zeolite complexes based on the selective, through-space, distance-dependent transfer of magnetization from protons in selectively deuterated organics to framework silicon nuclei. The method was developed using the known structure of the high-loaded ZSM-5/p-xylene complex containing p-xylene-d(6) or p-xylene-d(4). It was then applied to determine the unknown structure of the low-loaded ZSM-5/p-xylene complex using NMR alone. For the high-loaded complex improved data were obtained below 273 K, where slow motions and exchange processes of the p-xylene are eliminated. The general approach was validated by. the exact agreement of the experimental H-1-Si-29 CPMAS spectra obtained at a specific contact time and the complete 24-line spectra simulated using 1/T-CP vs M-2 correlations from only the six clearly resolved resonances. For the low-loaded complex the Si-29 resonances were assigned at 267 K, and variable contact time CP experiments were carried out between 243 and 173 K using the same specifically deuterated p-xylenes. All possible locations and orientations of the p-xylene guests were sampled, and those solutions that gave acceptable linear 1/T-CP vs M-2 correlations were selected. The optimum p-xylene location in this temperature range was determined to be in the channel intersection with the long molecular axis parallel to [0,1,0] (ring center fractional coordinates {-0.009, 0.250, 0.541}) with the ring plane oriented at an angle of 30 +/- 3 degrees about the crystallographic b axis. A subsequent single-crystal X-ray study confirmed this predicted structure.},
	keywords = {3-DIMENSIONAL BONDING CONNECTIVITIES, CROSS-POLARIZATION, CRYSTAL STRUCTURE-ANALYSIS, LATTICE, MAGIC-ANGLE, NATURAL-ABUNDANCE, NUCLEAR-MAGNETIC-RESONANCE, PROTON-ENHANCED NMR, SINGLE-CRYSTAL, SPINNING NMR, structures},
	isbn = {0002-7863},
	url = {<Go to ISI>://000229244600061},
	author = {Fyfe, C. A. and Diaz, A. C. and Grondey, H. and Lewis, A. R. and Forster, H.}
}
@article {716,
	title = {Dichloro(diphosphine)(2-pyridyl-ketone)ruthenium(II) complexes},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {81},
	number = {11},
	year = {2003},
	note = {ISI Document Delivery No.: 746YXTimes Cited: 9Cited Reference Count: 31},
	month = {Nov},
	pages = {1263-1269},
	type = {Article},
	abstract = {Described are the synthesis and characterization of Ru(II) complexes of the type RuCl2L2(N-O), where L-2 is either 1,4-bis(diphenylphosphino)butane (dppb) or (PPh3)(2), and N-O represents chelated 2-benzoylpyridine (2-bzpy) or 2-acetylpyridine (2-acpy); the Ru presursors used were [RuCl2(dppb)](2)(mu-dppb) or RuCl2(PPh3)(3). The crystal structure of cis-RuCl2(dppb)(2-bzpy) is presented, and three other RuCl2L2(N-O) complexes with cis-chlorines are isolated and characterized spectroscopically; of the trans-dichloro species, RuCl2(PPh3)(2)(N-O) complexes are isolated, while the corresponding dppb species are characterized in situ. In all cases, thermodynamically stable cis-complexes are formed from initially formed trans-species.},
	keywords = {2, 2-acetylpyridine, 2-benzoylpyridine, 2{\textquoteright}-BIPYRIDINE, CRYSTAL-STRUCTURE, DONOR, ISOMERIZATION, LIGANDS, phosphines, REDOX POTENTIALS, ruthenium, ruthenium complexes, structures, X-RAY},
	isbn = {0008-4042},
	url = {<Go to ISI>://000186777600018},
	author = {Queiroz, S. L. and Batista, A. A. and de Araujo, M. P. and Bianchini, R. C. and Oliva, G. and Ellena, J. and James, Brian R.}
}
@article {5098,
	title = {Dissecting the electrostatic interactions and pH-dependent activity of a family 11 glycosidase},
	journal = {Biochemistry},
	volume = {40},
	number = {34},
	year = {2001},
	note = {ISI Document Delivery No.: 466CYTimes Cited: 56Cited Reference Count: 50},
	month = {Aug},
	pages = {10115-10139},
	type = {Article},
	abstract = {Previous studies of the low molecular mass family 11 xylanase from Bacillus circulans show that the ionization state of the nucleophile (GIu78, pK(a) 4.6) and the acid/base catalyst (Glu 172, pK(a) 6.7) gives rise to its pH-dependent activity profile. Inspection of the crystal structure of BCX reveals that Glu78 and Glu172 are in very similar environments and are surrounded by several chemically equivalent and highly conserved active site residues. Hence, there are no obvious reasons why their apparent pKa values are different. To address this question, a mutagenic approach was implemented to determine what features establish the pKa values (measured directly by C-13 NMR and indirectly by pH-dependent activity profiles) of these two catalytic carboxylic acids. Analysis of several BCX variants indicates that the ionized form of Glu78 is preferentially stabilized over that of Glu 172 in part by stronger hydrogen bonds contributed by two well-ordered residues, namely, Tyr69 and Gln127. In addition, theoretical pKa calculations show that Glu78 has a lower pKa value than Glu 172 due to a smaller desolvation energy and more favorable background interactions with permanent partial charges and ionizable groups within the protein. The pKa value of Glu172 is in turn elevated due to electrostatic repulsion from the negatively charged glutamate at position 78. The results also indicate that all of the conserved active site residues act concertedly in establishing the pKa values of Glu78 and Glu 172, with no particular residue being singly more important than any of the others. In general, residues that contribute positive charges and hydrogen bonds serve to lower the pKa values of Glu78 and Glu172. The degree to which a hydrogen bond lowers a pKa value is largely dependent on the length of the hydrogen bond (shorter bonds lower pKa values more) and the chemical nature of the donor (COOH > OH > CONH2). In contrast, neighboring carboxyl groups can either lower or raise the pKa values of the catalytic glutamic acids depending upon the electrostatic linkage of the ionization constants of the residues involved in the interaction. While the pH optimum of BCX can be shifted from -1.1 to +0.6 pH units by mutating neighboring residues within the active site, activity is usually compromised due to the loss of important ground and/or transition state interactions. These results suggest that the pH optima of an enzyme might be best engineered by making strategic amino acid substitutions, at positions outside of the "core" active site, that electrostatically influence catalytic residues without perturbing their immediate structural environment.},
	keywords = {ASSIGNMENTS, BACILLUS-CIRCULANS XYLANASE, CATALYSIS, GLYCOSYL-ENZYME INTERMEDIATE, KINETIC-ANALYSIS, MASS-SPECTROMETRY, MECHANISMS, NMR, PK(A), PROTEIN, SITE NUCLEOPHILE, structures},
	isbn = {0006-2960},
	url = {<Go to ISI>://000170627800014},
	author = {Joshi, M. D. and Sidhu, G. and Nielsen, J. E. and Brayer, G. D. and Withers, S. G. and McIntosh, L. P.}
}
@article {3759,
	title = {Extended chain 2,3-pyrazinedicarboxylase complexes of manganese(II) and cadmium(II); Synthesis and structure and magnetic properties},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {74},
	number = {12},
	year = {1996},
	note = {ISI Document Delivery No.: WG452Times Cited: 26Cited Reference Count: 16},
	month = {Dec},
	pages = {2413-2423},
	type = {Article},
	abstract = {{Manganese and cadmium complexes of singly and doubly deprotonated 2,3-pyrazinedicarboxylic acid (pyzdcH(2)) have been prepared and studied. Crystal data: [H3O](2x)[Mn(pyzdc)(2)](x), 1, monoclinic, C2/(c) (no. 15)},
	keywords = {2, 3-pyrazinedicarboxylates, ANTIFERROMAGNETISM, CADMIUM, CATIONS, EXCHANGE, extended chains, LIGANDS, manganese, structures, X-RAY},
	isbn = {0008-4042},
	url = {<Go to ISI>://A1996WG45200003},
	author = {Mao, L. and Rettig, S. J. and Thompson, W. C. and Trotter, J. and Xia, S. H.}
}
@article {3643,
	title = {Synthesis of some phosphino- and arsinobenzenechromium tricarbonyl derivatives and metal carbonyl clusters},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {74},
	number = {11},
	year = {1996},
	note = {ISI Document Delivery No.: WC124Times Cited: 6Cited Reference Count: 36},
	month = {Nov},
	pages = {2167-2181},
	type = {Article},
	abstract = {{The synthesis of a number of new phosphino- and arsinobenzenechromium tricarbonyl ligands ER(2)C(6)H(5)Cr(CO)(3) (ER(2) = PEt(2), PPr2i, PBu(2)(t), PPh(2), AsPh(2) AsMe(2)), ER[C6H5Cr(CO)(3)](2) (ER = PEt, PBu(t), PPh, AsPh) has been achieved by reacting lithium derivatives of benzenechromium tricarbonyl with appropriate chlorophosphines or iodoarsines. The spectroscopic properties of these ligands are described. The structure of (Pr2PC6H5Cr)-P-i(CO)(3) was determined by an X-ray crystallographic study. This is the first solid state structure to be reported for a phosphinobenzenechromium tricarbonyl derivative. The structures of four metal carbonyl cluster complexes were also determined. Crystals of (Pr2PC6H5Cr)-P-i(CO)(3) (3, C15H19CrO3P) are monoclinic, space group P2(1)/c},
	keywords = {(BENZYNE)CHROMIUM, arsinobenzenechromium tricarbonyl derivatives, CHEMISTRY, COMPLEXES, CRYSTAL, DERIVATIVES, LIGAND-SUBSTITUTED DERIVATIVES, metal carbonyl clusters, OS3(CO)12, P(OCH2CF3)3, phosphinobenzenechromium tricarbonyl, RU3(CO)12, STEREOCHEMISTRY, structures, TRICARBONYL, X-ray structures},
	isbn = {0008-4042},
	url = {<Go to ISI>://A1996WC12400031},
	author = {Cullen, W. R. and Rettig, S. J. and Zhang, H. L.}
}
@article {3398,
	title = {STRUCTURAL STUDIES OF ORGANOBORON COMPOUNDS .63. REACTION OF KETOXIMES WITH ALDEHYDES AND DIPHENYLBORINIC ACID, AND THE CRYSTAL AND MOLECULAR-STRUCTURES OF 2 DIFFERENT TYPES OF BORON CHELATES AND ONE OF THE PRECURSOR ALDEHYDE ADDUCTS},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {73},
	number = {6},
	year = {1995},
	note = {ISI Document Delivery No.: RM831Times Cited: 12Cited Reference Count: 48},
	month = {Jun},
	pages = {835-845},
	type = {Article},
	abstract = {{The diphenylboron chelates of ketoxime adducts to formaldehyde and trichloroacetaldehyde (chloral) have been synthesized. The reactions were carried out as three-component one-pot reactions, and also as two-step reactions for the ketoxime chloral adducts, which were isolated and characterized before reaction with oxybis(diphenylborane) to form the diphenylboron chelates. One of the intermediate adducts and two of the diphenylboron chelates have been characterized by X-ray crystallographic analysis. Crystals of O-(2,2,2-trichloro-1-hydroxyethyl)-2-propanonoxime, 8d, are monoclinic},
	keywords = {BORON CHELATES, BORON COMPOUNDS, CRYSTAL, N-(2-HYDROXYALKYL)NITRONES, NITRONES, ORGANBORON COMPOUNDS, RING-CHAIN ISOMERISM, structures},
	isbn = {0008-4042},
	url = {<Go to ISI>://A1995RM83100010},
	author = {Kliegel, W. and Riebe, U. and Rettig, S. J. and Trotter, J.}
}
