Studies on the coordination chemistry of iridium and platinum
Studies on the coordination chemistry of iridium and platinum
The iridium (IE) anions trans- [M^CL;]" (L = pyridine, PEt3, PEt2Ph, PEtPh2, AsEt3, AsMe2Ph, SMe2 or SeMe2) have been prepared and oxidised with chlorine to the purple iridium (TV) complexes fra/ts-flrlvjCU]. Dark green trans-lltL^BT^] (L = pyridine, PEt3, PMe2Ph, AsEt3, AsMe2Ph or SMe2) were prepared similarly from [IrL2Br4]~ and Br2 or HNO3. The [IrLaCU] (L = PPh3, AsPh3 or SbPh3) are produced by chlorination of [(IrL^Cls)!!]. The complexes cis- [IrL2Q4] (L = pyridine or SbMes) and cis-[Ir(py)2Br4] were also prepared. The iridium (DI) complexes 0wiy-[Ir(TeMe2Cl4]~ and [Ir(SeMe2)2Br~ were also prepared but did not give the desired product on oxidation. Two complexes of the type [IrLCls]" (L = pyridine, SPh2) were obtained but no others could be prepared. The complexes [Ir(L-L)Cl4] [(L-L) = 1,10-phenanthroline, 2,2'- bipyridyl, dithioether or diselenoether] were made by oxidation of the iridate (III) analogues as were the bromo-complexes [Ir(L-L)Br4] [(L-L) = 2,2'-bipyridyl or 1,10- phenanthroline]. The complexes [Ir(RTe(CH2)3TeR)Cl4]- (R = Me or Ph), [Ir(MeSCH2CH2SMe)Br4]-and [Ir(PhSeCH2CH2SePh)Br4]~ were prepared but did not oxidise cleanly. Analogues with diphosphines, diarsines and distibines could not be made. All complexes were characterised by elemental analysis, i.r. and electronic spectroscopies and, where appropriate, multinuclear n.m.r. spectroscopies. Single crystal X-ray studies of [Ir(AsEt3)2Br4] and FXphenJCU] are reported. The redox behaviour of the Ir(III)/Ir(rV) couples was investigated by cyclic voltammetry; most of the complexes exhibiting reversible electron transfer.
A series of platinum (II) and platinum (TV) complexes of bi- and mul-tidentate phosphorus, arsenic and sulphur ligands were examined by Pt-19S n.m.r. spectroscopy. The chemical shift 5(Pt) varies with neutral donor and halide but is little affected by chelate ring size. The materials [Pt(L-L)Li] arc shown to exist as [Pt(L-L)I2] in dmso but [Pt(o-CH(AM))l]2+ is a genuine Pt(IV) iodo complex. (DX84409)
University of Southampton
1988
Powell, Nigel Anthony
(1988)
Studies on the coordination chemistry of iridium and platinum.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The iridium (IE) anions trans- [M^CL;]" (L = pyridine, PEt3, PEt2Ph, PEtPh2, AsEt3, AsMe2Ph, SMe2 or SeMe2) have been prepared and oxidised with chlorine to the purple iridium (TV) complexes fra/ts-flrlvjCU]. Dark green trans-lltL^BT^] (L = pyridine, PEt3, PMe2Ph, AsEt3, AsMe2Ph or SMe2) were prepared similarly from [IrL2Br4]~ and Br2 or HNO3. The [IrLaCU] (L = PPh3, AsPh3 or SbPh3) are produced by chlorination of [(IrL^Cls)!!]. The complexes cis- [IrL2Q4] (L = pyridine or SbMes) and cis-[Ir(py)2Br4] were also prepared. The iridium (DI) complexes 0wiy-[Ir(TeMe2Cl4]~ and [Ir(SeMe2)2Br~ were also prepared but did not give the desired product on oxidation. Two complexes of the type [IrLCls]" (L = pyridine, SPh2) were obtained but no others could be prepared. The complexes [Ir(L-L)Cl4] [(L-L) = 1,10-phenanthroline, 2,2'- bipyridyl, dithioether or diselenoether] were made by oxidation of the iridate (III) analogues as were the bromo-complexes [Ir(L-L)Br4] [(L-L) = 2,2'-bipyridyl or 1,10- phenanthroline]. The complexes [Ir(RTe(CH2)3TeR)Cl4]- (R = Me or Ph), [Ir(MeSCH2CH2SMe)Br4]-and [Ir(PhSeCH2CH2SePh)Br4]~ were prepared but did not oxidise cleanly. Analogues with diphosphines, diarsines and distibines could not be made. All complexes were characterised by elemental analysis, i.r. and electronic spectroscopies and, where appropriate, multinuclear n.m.r. spectroscopies. Single crystal X-ray studies of [Ir(AsEt3)2Br4] and FXphenJCU] are reported. The redox behaviour of the Ir(III)/Ir(rV) couples was investigated by cyclic voltammetry; most of the complexes exhibiting reversible electron transfer.
A series of platinum (II) and platinum (TV) complexes of bi- and mul-tidentate phosphorus, arsenic and sulphur ligands were examined by Pt-19S n.m.r. spectroscopy. The chemical shift 5(Pt) varies with neutral donor and halide but is little affected by chelate ring size. The materials [Pt(L-L)Li] arc shown to exist as [Pt(L-L)I2] in dmso but [Pt(o-CH(AM))l]2+ is a genuine Pt(IV) iodo complex. (DX84409)
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Published date: 1988
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Local EPrints ID: 460846
URI: http://eprints.soton.ac.uk/id/eprint/460846
PURE UUID: 50ce4278-9b48-47d6-87bb-61c1e0c740bf
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Date deposited: 04 Jul 2022 18:30
Last modified: 04 Jul 2022 18:30
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Author:
Nigel Anthony Powell
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