SPECTRAL AND PHOTOCHEMICAL BEHAVIOR OF MONONUCLEAR AND DINUCLEAR ALPHA-DIIMINE COMPLEXES OF PT(II) AND PD(II) WITH CATECHOL DERIVATIVES
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Title |
SPECTRAL AND PHOTOCHEMICAL BEHAVIOR OF MONONUCLEAR AND DINUCLEAR ALPHA-DIIMINE COMPLEXES OF PT(II) AND PD(II) WITH CATECHOL DERIVATIVES
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Creator |
ANBALAGAN, V
SRIVASTAVA, TS |
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Subject |
mixed-ligand palladium(ii)
transition-metal complexes platinum(ii) complexes singlet oxygen photosensitizers o-1(2) 1,10-phenanthroline luminescence generation porphyrins mononuclear alpha-diimine complexes dinuclear alpha-diimine complexes catechol derivatives |
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Description |
Mononuclear and dinuclear complexes with the formulae [M(DHB)(N-N)] (where M = Pd(II) or Pt(II); N-N = 2,2'-bipyridine (BPY), 2,2'-biquinoline (BIQ), 4,7-diphenyl-1,10-phenanthroline (DPP) or 1,10-phenanthroline (PHEN); DHB is the dianion of 3,4-dihydroxybenzaldehyde) and [{M(BPY)}(2)(THB)] (where M = Pd(II) or Pt(II); BPY is 2,2'-bipyridine; THB is the tetraanion of 3,3,4,4-tetrahydroxybenzaldazine) photosensitize the oxidation of 2,2,6,6-tetramethyl-4-piperidinol (XH) in N,N-dimethylformamide (DMF) to give 4-hydroxy-2,2,6,6-tetramethyl-4-piperidinyloxy, a nitroxide free radical (XO). This photo-oxidation reaction involves singlet molecular oxygen (O-1(2)) as an intermediate and its presence is confirmed by quenching studies using bis(diethyldithiocarbamato)nickel(II) (Ni(DDTC)2), a physical quencher of O-1(2). The ability of the mononuclear complexes to photosensitize the above photo-oxidation reaction follows the order: [Pt(DHB)(PHEN)] > [Pt(DHB)(DPP)] > [Pt(DHB)(BIQ)] > [Pt(DHB)(BPY)] > [Pd(DHB)(DPP)] greater than or equal to [Pd(DHB)(PHEN)] > [Pd(DHB)(BIQ) ]greater than or equal to [Pd(DHB)(BPY)]. Moreover, the dinuclear complexes, in comparison with the analogous mononuclear complexes, follow the order: [{Pt(BPY)}(2)(THB)]> [Pt(DHB)(BPY)] > [{Pd(BPY)}(2)(DHB)] > [Pd(DHB)(BPY)]. These orders depend on the metal ion, the number of metal ions in the complex, the nature of the alpha-diimine ligand and the distortion from planar geometry of the metal complex
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Publisher |
ELSEVIER SCIENCE SA LAUSANNE
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Date |
2011-07-29T13:12:52Z
2011-12-26T12:48:43Z 2011-12-27T05:50:55Z 2011-07-29T13:12:52Z 2011-12-26T12:48:43Z 2011-12-27T05:50:55Z 1995 |
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Type |
Article
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Identifier |
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 89(2), 113-119
1010-6030 http://dx.doi.org/10.1016/1010-6030(94)04005-M http://dspace.library.iitb.ac.in/xmlui/handle/10054/7723 http://hdl.handle.net/10054/7723 |
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Language |
en
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