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Titolo:
Solution and solid state behaviour of binuclear mercury(II) compounds containing cis,trans,cis-1,2,3,4-tetrakis(diphenylphosphino)cyclobutane: first X-ray structural characterisation of mercury(II) complexes with two different chelating phosphines
Autore:
Oberhauser, W; Stampfl, T; Haid, R; Langes, C; Bachmann, C; Kopacka, H; Ongania, KH; Bruggeller, P;
Indirizzi:
Innsbruck Univ, Inst Allgemeine Anorgan & Theoret Chem, A-6020 Innsbruck, Austria Innsbruck Univ Innsbruck Austria A-6020 Chem, A-6020 Innsbruck, Austria Innsbruck Univ, Inst Organ Chem, A-6020 Innsbruck, Austria Innsbruck UnivInnsbruck Austria A-6020 Chem, A-6020 Innsbruck, Austria
Titolo Testata:
POLYHEDRON
fascicolo: 7-8, volume: 20, anno: 2001,
pagine: 727 - 740
SICI:
0277-5387(20010415)20:7-8<727:SASSBO>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
CRYSTAL-STRUCTURES; TERTIARY PHOSPHINES; MOLECULAR-STRUCTURE; HALIDE-COMPLEXES; PLATINUM(II) COMPLEXES; P-31 NMR; TETRADENTATE PHOSPHINE; METAL-COMPLEXES; LIGAND NP3; PALLADIUM(II);
Keywords:
crystal structures; mercury complexes; tetraphosphine complexes; diphosphine complexes; bimetallic complexes; tetrahedral coordination;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
54
Recensione:
Indirizzi per estratti:
Indirizzo: Bruggeller, P Innsbruck Univ, Inst Allgemeine Anorgan & Theoret Chem, Innrain 52A, A-6020 Innsbruck, Austria Innsbruck Univ Innrain 52A Innsbruck Austria A-6020 Austria
Citazione:
W. Oberhauser et al., "Solution and solid state behaviour of binuclear mercury(II) compounds containing cis,trans,cis-1,2,3,4-tetrakis(diphenylphosphino)cyclobutane: first X-ray structural characterisation of mercury(II) complexes with two different chelating phosphines", POLYHEDRON, 20(7-8), 2001, pp. 727-740

Abstract

Several novel binuclear Hg-II complexes of cis,trans,cis-1,2,3,4-tetrakis(diphenylpho sphino)cyclobutane (dppcb) have been prepared and characterisedby X-ray diffraction methods, NMR spectroscopy (Hg-199{H-1}, P-31{H-1},H-1), FAB mass spectrometry, IR spectroscopy, elemental analyses and melting points. The tetrahedral coordination of both the Hg-II centres in the homobimetallic compounds [Hg2L4(dppcb)] (L = Cl- (1), Br- (2), CN- (3), NO3- (4)), synthesised by the reaction of HgL2 with dppcb, is indicated by their solution NMR parameters and is confirmed by the X-ray structures of 1-3. Though the Fermi contact term is not always dominant in determining (1)J(Hg,P), the NMR parameters are correlated to the changes in the bond lengths and angles in 1-3. A comparison is given with correlations derived from similar complexes. The reaction of 4 with 2,2 ' -bipyridine (bipy) or 1,10-phenanthroline (phen) leads to [Hg-2(dppcb)(bipy)(2)] (NO3)(4) (5) and [Hg-2(dppcb)(phen)(2)](NO3)(4) (8). Also, for 5 and 6 the NMR data and FAB mass spectra are in agreement with tetrahedral Hg-II centres. The treatment of 4 with monophosphines produces trans -[Hg-2(NO3)(2)(dppcb)L-2'] (NO3)(2) (L ' = P(CH2Ph)(3) (7), P(CH2CH2CN)(3) (8), PPh3 (9)). In 7-9 the typical large (1)J(Hg,P) values are observed for the monophosphines compared with the corresponding parameters for chelating dppcb, which are reduced due to the five-membered ring formation. In the reaction of 4 with the diphosphine Ph2PCH2PPh2 (dppm) and the subsequent metathesis with LiAsF6, trans-[Hg-2(NO3)(2)(dppcb)(eta (1)-dppm)(2)](AsF6)(2) (10) is formed. The X-ray structure of 10 showing coordinated and dangling phosphorus atoms of dppm is the first completecharacterisation of a Hg-II complex containing two different chelating phosphines. Though in solution the dppm ligands are involved in fast intramolecular end-over-end exchange, the solution structure of 10 corresponds to its solid state structure, which is indicated by unusual (1)J(Hg,P) values. Catalytic amounts of Hg-II convert trans-[Hg-2(NO3)(2)(dppcb) (eta (1)-dppm)(2)](NO3)(2) into trans-[Hg-2(NO3)(2)(dppcb) (eta (1)-P-dppmO)(2)](NO3)(2) (11), where dppmO is Ph2PCH2P(O)Ph-2. The X-ray structure of 11 is the first complete characterisation of a Hg-II compound consisting of chelating phosphine together with phosphinoyl moieties. The solid state structure and the solution NMR parameters of 11 clearly show the presence of a dangling -P(O)Ph-2 group. The complexes 1-11 illustrate the tendency that polydentate donor ligands often geometrically and entropically restrict the number of accessible structures for Hg-II. Especially, the X-ray structures of 1-3, 10,and 11 indicate the preference of Hg-II for tetrahedral and trigonal pyramidal coordinations in compounds containing dppcb. (C) 2001 Elsevier ScienceB.V. All rights reserved.

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Documento generato il 27/09/20 alle ore 01:05:20