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Sevagapandian Sankarapandian Rajagopal Gurusamy Nehru Kasi Athappan Periakaruppan 《Transition Metal Chemistry》2000,25(4):388-393
Complexes of the general formula, ML2 [M = CuII, NiII, CoII and OVIV; L = 1,2,3,5,6,7,8,8a-octahydro-3-hydroxyimino-N-(4-X-phenyl)-l-phenyl-5-(phenylmethylene)-2-naphthalenecarboxamide (X =
H, Me, OMe, Cl)] have been prepared and characterized on the basis of elemental analysis, magnetic moments and i.r., e.p.r.
and electronic spectra. These metal complexes contain the N4 chromophore with the ligand coordinating through nitrogens of the azomethine and deprotonated anilide functions. C.v. measurements
indicate that the copper(II) complexes are quasi-reversible in acetonitrile solution. Square planar and square pyramidal structures
are assigned respectively to the copper(II) and oxovanadium(IV) complexes, whereas tetrahedral geometry is assigned to the
nickel(II) and cobalt(II) complexes. Deprotonated anilide nitrogen is involved in coordination and the presence of an electron-donating
group para to the anilide function decreases the ΔE values of the d–d transitions while the value is found to increase when electron-withdrawing groups are substituted. Line
spacing in the e.p.r. spectra of the copper(II) and oxovanadium(IV) complexes increases when methyl group is para to the anilide group, and decreases when this group is replaced by methoxy or chloro. The ν(C–N) of the anilide group and
the ν(C-N) of the azomethine function of the oxime metal complexes are metal-sensitive and the blue shift for the above stretching
frequencies follows the order: copper(II) > oxovanadium(IV) > nickel(II) ≈ cobalt(II).
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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H. K. Shobha H. Johnson M. Sankarapandian Y. S. Kim P. Rangarajan D. G. Baird J. E. McGrath 《Journal of polymer science. Part A, Polymer chemistry》2001,39(17):2904-2910
The synthesis of aromatic polyphosphonates based on the step polymerization of various bisphenols and dichlorophenyl phosphine oxide was investigated. The effect of catalyst, type, concentration, and polymerization time were systematically varied to obtain high molecular weight polymers. Very high molecular weight tough, ductile materials with a high degree of optical clarity were synthesized. In contrast with the aromatic polycarbonates, the refractive index was increased from 1.58 to 1.60 (for the bisphenol A‐based system) and 1.64 for a biphenol‐based system. The latter was still an amorphous soluble polymer as a result of the non‐coplanar nature of the phenyl phosphine oxide bond, unlike the analogous polycarbonate. Hydrolytically stable melt‐processable cumyl phenol end‐capped polyphosphonates were successfully achieved for the first time. Rheological studies show that these end‐capped systems are melt‐stable at 200 °C, whereas the systems of initially higher molecular weight but without any well‐defined end capping clearly degraded quickly probably as a result of an acid‐catalyzed hydrolysis process. Extensive high char yields were produced upon pyrolysis in either nitrogen or air, suggesting good fire resistance. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2904–2910, 2001 相似文献
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Periakaruppan Athappan Sankarapandian Sevagapandian Gurusamy Rajagopal 《Transition Metal Chemistry》1995,20(5):472-476
Summary Metal(II) chelates of Schiff bases derived from the condensation of 1,2,3,5,6,7,8,8a-octahydro-3-oxo-N,1-diphenyl-5-(phenylmethylene)-2-naphthalenecarboxamide with o-aminophenol (KAAP), o-aminothiophenol (KAAT) or o-aminobenzoic acid (KAAB) have been prepared and characterized. The complexes are of the type [M(N2X)]2 for M = CuII and M(NX)2·nH2O for M = NiII, CoII and VOII (X = phenolic oxygen, thiophenolic sulphur or carboxylic oxygen; n = 0 or 2). Conductivity data indicate that the complexes are non-ionic. The Schiff bases behave as dibasic tridentate ligands in their copper(II) complexes and as monobasic bidentate ligands in their nickel(II), cobalt(II) and vanadyl(II) complexes. The subnormal magnetic moments of the copper(II) complexes are ascribed to an antiferromagnetic exchange interaction arising from dimerization. Nickel(II) and cobalt(II) complexes are trans octahedral whereas vanadyl(II) complexes are square pyramidal 相似文献
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