@article {1011, title = {Comparison of anti-hyperglycemic effect amongst vanadium, molybdenum and other metal maltol complexes}, journal = {Journal of Inorganic Biochemistry}, volume = {98}, number = {5}, year = {2004}, note = {ISI Document Delivery No.: 824HVTimes Cited: 37Cited Reference Count: 7411th International Conference on Biological Inorganic ChemistryJUL 19-23, 2003Cairns, AUSTRALIA}, month = {May}, pages = {683-690}, type = {Proceedings Paper}, abstract = {A wide variety of vanadium-containing complexes have been tested, both in vivo and in vitro, as possible therapeutic agents for the oral treatment of type 2 diabetes mellitus. None so far has surpassed bis(maltolato)oxovanadium(IV) (BMOV) for glucose- and lipid-lowering in an orally available formulation. Ligand choice is clearly an important factor in pharmacological efficacy of vanadium compounds as insulin enhancing agents. In this study, we kept the ligand and dose the same, varying instead the metal ion bound to the maltolato ligand in a series of binary complexes of neutral charge. A requirement for vanadyl ion as the metal ion of choice was apparent; no other metal ion tested served as a suitable substitute. Amongst [MoO2](2+), Co(II), Cu(II), Cr(III), and Zn(II), only [MoO2](2+) and Co(II) showed any hypoglycemic activity at the ED50 dose for bis(maltolato)oxovanadium(IV), 0.6 mmol kg(-1) by oral gavage in streptozotocin (STZ)-diabetic rats within 72 It of administration of compound. (C) 2004 Elsevier Inc. All rights reserved.}, keywords = {ABSORPTION, CHROMIUM, cobalt, COORDINATION MODE, copper, DEPENDENT DIABETES-MELLITUS, GLUCOSE-METABOLISM, IN-VIVO, INSULIN, LIPID-METABOLISM, MOLYBDENUM, RATS, VANADIUM, zinc, ZINC SUPPLEMENTATION}, isbn = {0162-0134}, url = {://000221678300004}, author = {Thompson, K. H. and Chiles, J. and Yuen, V. G. and Tse, J. and McNeill, J. H. and Orvig, Chris} } @article {4933, title = {pi-bonding and reactivity in transition metal nitrosyl complexes, Part 7 - Effects of pi-bonding on stability and reactivity in [CpCr(NO)] complexes}, journal = {Chemistry-a European Journal}, volume = {6}, number = {9}, year = {2000}, note = {ISI Document Delivery No.: 312WWTimes Cited: 3Cited Reference Count: 21}, month = {May}, pages = {1525-1529}, type = {Article}, abstract = {Recent synthetic and theoretical investigations of organometallic compounds containing the CpCr(NO) fragment have shown an interdependence of the electronic nature of ancillary ligands and the stability of a given Cr oxidation state. Understanding the correlation between ligand cc-bonding properties and the nature of the metal-based frontier orbitals permits the rationalization of observed reactivity patterns, and the identification and preparation of new classes of target molecules.}, keywords = {CHEMISTRY, CHROMIUM, LIGAND, ligand effects, NITROSYL COMPLEXES, pi-interactions, REDOX, SPIN-STATE}, isbn = {0947-6539}, url = {://000086967800002}, author = {Smith, K. M. and McNeil, W. S. and Legzdins,Peter} } @article {4865, title = {Synthesis, structure and magnetic properties of a chromium(III)-nicotinamide complex [Cr3O(O2CCH3)(6)(na)(3)](+) (na = nicotinamide)}, journal = {Inorganica Chimica Acta}, volume = {297}, number = {1-2}, year = {2000}, note = {ISI Document Delivery No.: 277TNTimes Cited: 16Cited Reference Count: 20}, month = {Jan}, pages = {1-5}, type = {Article}, abstract = {The reaction between [Cr3O(O2CCH3)(7)(H2O)] ({\textquoteright}basic chromium acetate{\textquoteright}) and an excess of nicotinamide (na) at 120 degrees C, followed by dissolution of the mixture in water and addition of PF6-, led to the isolation of the first Cr(III)-nicotinamide complex [Cr3O(O2CCH3)(6)(na)(3)](+) (1). Crystals of the compound 1 . PF6. 3CH(3)CN were subjected to a detailed X-ray structural analysis. The three N-bonded na ligands, which occupy axial positions at the corners of the triangular basic chromium acetate, are nearly co-planar with the Cr3O system. The three Cr-N(na) bond distances are in the range 2.121(8)-2.128(8) Angstrom. Two of the na ligands on each cluster form four hydrogen bonds with two ligands from a neighboring cluster, via their amide ends with N...O distances of 2.88(1)-2.92(1) Angstrom. Magnetic susceptibility measurements of a powdered sample of 1 . PF6. 3CH(3)CN over the range 2-300 K showed that the three Cr(III) ions were antiferromagnetically coupled with J -10.4 cm(-1). There was no evidence for intermolecular magnetic exchange between the two Cr3O centers which are connected via hydrogen bonds. (C) 2000 Elsevier Science S.A. All rights reserved.}, keywords = {CHROMIUM, CHROMIUM COMPLEXES, crystal structures, GLUCOSE-TOLERANCE FACTOR, MAGNETIC PROPERTIES, nicotinamide complexes}, isbn = {0020-1693}, url = {://000084949800002}, author = {Lieberman, R. L. and Bino, A. and Mirsky, N. and Summers, D. A. and Thompson, R. C.} } @article {3417, title = {CHARACTERISTIC PHYSICAL AND CHEMICAL-PROPERTIES OF THE 17-VALENCE-ELECTRON ALKYL COMPLEXES CPCR(NO)(L)R}, journal = {Organometallics}, volume = {14}, number = {10}, year = {1995}, note = {ISI Document Delivery No.: RY971Times Cited: 10Cited Reference Count: 59}, month = {Oct}, pages = {4721-4731}, type = {Article}, abstract = {{CpCr(NO)(L)R 17-valence-electron complexes (L = Lewis base}, keywords = {19-ELECTRON COMPLEXES, CHROMIUM, {17-ELECTRON}, isbn = {0276-7333}, url = {://A1995RY97100039}, author = {Legzdins,Peter and Shaw, M. J. and Batchelor, R. J. and Einstein, F. W. B.} } @article {3159, title = {THE INFLUENCE OF ACCELERATED FIXATION ON THE STABILITY OF CHROMIUM(V) IN CCA-TREATED WOOD}, journal = {Holzforschung}, volume = {48}, number = {1}, year = {1994}, note = {ISI Document Delivery No.: MU809Times Cited: 14Cited Reference Count: 12}, pages = {1-3}, type = {Article}, abstract = {Ponderosa pine match stick specimens were impregnated with chromated-copperarsenate preservative (CCA) and the treated wood subjected to, storing under ambient conditions, oven drying or steam treatment. The samples were analyzed by electron spin resonance spectrometry (ESR). Accelerated fixation of CCA by steam treatment initially produced a strong chromium(V) ESR signal, which quickly decreased. Complete reduction of Cr(VI) to Cr(III) was achieved in 2 hours by steaming. Samples stored under ambient conditions still exhibited a moderately strong chromium(V) signal after 44 days. Oven drying of the CCA-treated samples for four days, failed to convert all of the chromium(V) intermediate to the trivalent form. Leaching of CCA-treated samples, confirmed that fixation was best achieved with the steam treatment. Oven drying caused the samples to leach large amounts of copper and smaller amounts of chromium and arsenic.}, keywords = {CCA, CHROMIUM, ESR, PRESERVATIVE FIXATION}, isbn = {0018-3830}, url = {://A1994MU80900001}, author = {Ruddick, J. N. R. and Yamamoto, K. and Herring, F. G.} } @article {2854, title = {TETRAPHENYLCYCLOPENTADIENYL NITROSYL COMPLEXES OF MOLYBDENUM AND TUNGSTEN}, journal = {Organometallics}, volume = {12}, number = {4}, year = {1993}, note = {ISI Document Delivery No.: KX233Times Cited: 8Cited Reference Count: 40}, month = {Apr}, pages = {1029-1037}, type = {Article}, abstract = {{Sequential treatment Of M(CO)6 (M = MO, W) in THF with Cp(phi)Li (Cp(phi) = eta5-C5Ph4H) and Diazald (N-methyl-N-nitroso-p-toluenesulfonamide) affords good yields of Cp(phi)M(NO)(CO)2 which convert to Cp(phi)M(NO)Cl2 upon treatment with PCl5 in Et2O. Dialkyl compounds of the type Cp$\#$M(NO)R2 (R = CH2SiMe3, CH2Ph) are readily preparable from these dichloro precursors by straight forward metathesis reactions. Finally, molybdenum dinitrosyl complexes of the type Cp(phi)Mo(NO)2X (X = Cl, Ph) are obtained when Cp(phi)Mo(NO) (CO)2 is reacted with [NO] [PF6] in CH2Cl2 and the resulting [Cp(chi)Mo(NO)2]PF6 intermediate salt is treated in situ with a source of X-. All new complexes have been characterized by conventional means, and an X-ray crystallographic analysis of CP(phi)W(NO)(CH2SiMe3)2 has been performed. Crystal data for Cp(phi)W(NO)(CH2SiMe3)2: triclinic, space group P1BAR}, keywords = {CHEMISTRY, CHROMIUM, CYCLOPENTADIENYL, PHYSICAL-PROPERTIES, REDUCTION}, isbn = {0276-7333}, url = {://A1993KX23300017}, author = {Legzdins,Peter and Reina, R. and Shaw, M. J. and Batchelor, R. J. and Einstein, F. W. B.} } @article {6989, title = {ORGANOMETALLIC NITROSYL CHEMISTRY .47. CYCLOPENTADIENYL(ETA(4)-TRANS-DIENE)NITROSYLMOLYBDENUM COMPLEXES AND THEIR REACTIVITIES TOWARD ACETYLENES AND PROTONIC ACIDS}, journal = {Organometallics}, volume = {10}, number = {9}, year = {1991}, note = {ISI Document Delivery No.: GF405Times Cited: 19Cited Reference Count: 25}, month = {Sep}, pages = {3070-3080}, type = {Article}, abstract = {{Reduction of [Cp*Mo(NO)I2]2 [CP* = eta-5-C5Me5] by sodium amalgam in THF at -30-degrees-C in the presence of an isomeric mixture of (E)- and (Z)-1,3-pentadiene affords two isolable isomers of Cp*Mo(NO)(eta-4-trans-1,3-pentadiene), one yellow (1A) and one red (1B). The most significant feature of the solid-state molecular structure of 1A is the fact that the transoidal (E)-1,3-pentadiene ligand is coordinated to the molybdenum with its methyl substituent pointing away from the cyclopentadienyl ring. The spectroscopic properties of 1B are consistent with it possessing a similar orientation of its (Z)-1,3-diene methyl substituent. This observation establishes that even though the Cp*Mo(NO) fragment in 1A and 1B exerts the electronic influence to bind the diene ligands in a twisted, transoidal fashion, steric interactions determine which face of the diene ligand can best accommodate this electronic requirement. Cyclic voltammetry studies have been carried out on two representative diene-containing compounds, namely CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) and CpMo(NO)(eta-4-cis-2,3-dimethylbutadiene) (Cp = eta-5-C5H5), in order to establish the redox properties of these types of complexes. The cyclic voltammograms indicate that both diene complexes are reasonably stable with respect to addition of electrons, since no reduction behavior is observed to the limit of the CH2Cl2 solvent (ca. -2 V). On the other hand, each of the complexes is quite readily oxidized and each exhibits three irreversible oxidations before the solvent limit of ca. +2 V. These redox properties are in accord with the results of Fenske-Hall molecular orbital calculations previously performed on the CpMo(NO)(eta-4-butadiene) model systems. Consistently, CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) does not undergo concomitant reduction when treated with acetylenes but rather effects a coupling between the diene ligand and the alkyne to produce a eta-4 (eta-3, eta-1) ligand in which the eta-3-allyl portion of the ligand is oriented endo with respect to the cyclopentadienyl ring. Thus, when the alkyne employed is 1-phenylpropyne, the resulting complex is CpMo(NO)[eta-4-C(Me)2CHCHC(Me)2C(Me)C(Ph)] (2), whose molecular structure has been established by specialized NMR spectroscopic techniques and by single-crystal X-ray crystallography. The reaction between CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) and 1,7-octadiyne affords two major isomers of a similar organometallic product. Finally, the isolable products of the reactions between CpMo(NO)(eta-4-trans-diene) and HX (diene = 2,5-dimethyl-2,4-hexadiene}, keywords = {ALKYNES, CHEMICAL-PROPERTIES, CHROMIUM, DIENES, LIGANDS}, isbn = {0276-7333}, url = {://A1991GF40500020}, author = {Christensen, N. J. and Legzdins,Peter and Einstein, F. W. B. and Jones, R. H.} }