Ian E. Niven

The donor properties of some α, ω-bis(diphenylphosphino)alkanes towards palladium(II). Polymeric, dimeric and monomeric trans-chelated complexes

Abstract Palladium(II) complexes of 1,6-bis(diphenylphosphino)hexane (dph), 1,8-bis(disphenylphosphino)octane (dpo), 1,10-bis(disphenylphosphino)decane (dpd), and 1,12-bis(disphenylphosphino)dodecane (dpdop) have been isolated. The structures of the complexes seem to be a function of the length of the alkane chain between the donor atoms; generally dph bridges two palladium atoms and forms polymeric complexes, dpo and dpd bridge two palladium atoms and form dimeric 22- or 26-membered rings and dpod acts as a trans -chelating ligand and forms a monomeric complex containing a 15-membered ring.

Palladium(II) and platinum(II) complexes of monodentate tertiary stibines

Abstract The ligands R 3 Sb (R = Et, cyclohexyl) and Ar 3 Sb (Ar = Ph; o,-m-, p-tolyl) form conventional planar palladium(II) and platinum(II) complexes, ML 2 X 2 (X = Cl, Br, I, SCN, NO 2 ). With bulky ligands such as cy 3 Sb and o-toyl 3 Sb it is found that complexes with trans geometry form, whereas the less bulky ligands generally form cis -platinum and cis -palladium chloro- and bromo-complexes. The thiocyanate complexes appear to undergo rearrangements in solution and complex equilibria are set up. The unique [Pt(Sbo-tolyl 3 ) 2 (SCN)(NCS)] has been isolated.

Four- and five-coordinate platinum(II) complexes with diphenylmethyl- and phenyldimethyl-stibine

Abstract The ligands SbPh 2 Me and SbPhMe 2 form conventional platinum(II) complexes, cis-PtL 2 X 2 (X = Cl, Br. I). In addition, the unusual purple five-coordinate complexes PtL 3 I 2 are formed in the solid state. These dissociate in solution by loss of ligand (L = SbPh 2 Me) or of iodide (L = SbPhMe 2 ). The presumably four-coordinate Pt( Sb Ph Me 2 ) 4 Cl 2 is also reported.

Studies in Mössbauer spectroscopy. Part 11. Antimony-121 spectra of some complexes of palladium(II) and platinum(II) with tertiary stibines

Antimony-121 Mossbauer spectra have been obtained for 23 complexes of the type [MX2L2][L = SbPh3, Sb(C6H4Me-p)3, Sb(C6H4Me-o)3, SbEt3, or Sb(C6H11)3; M = Pd or Pt; X = Cl, I, or NO2], for the five-co-ordinate [Ptl2L3](L = SbMePh2 or SbMe2Ph), for [RhCl3(SbPh3)3], and for the free triarylstibines. In each case co-ordination results in a large increase in isomer shift and a decrease in quadrupole coupling constant, as expected for substantial removal of electron density from the lone pair on the antimony atom. In conjunction with far-i.r. data, configurations are assigned to the square-planar complexes, which are cis unless the stibine is sterically demanding. The cis and trans influences of the halides on the electron density on the antimony atom are shown to be opposed.

Studies in Mössbauer spectroscopy. Part 8. Iron-57 spectra of some substituted tricarbonylnitrosyliron derivative

Iron-57 Mossbauer spectra have been obtained for several compounds in which Fe(CO)2(NO)L groups (L = CO, tertiary phosphine or arsine) are bonded to mercury, lead, or gold, Trends in the data are discussed in terms of the bonding characteristics of the ligands, and σ-bonding effects are found to predominate.

complexes of bidentate group vb chelates XX. Mass spectral studies in some diphosphine and distibine ligands with backbones of varying length

Abstract The mass spectral fragmentation patterns of the diphosphines Ph 2 P(CH 2 ) n PPh 2 ( n = 6, 8, 10, 12) and the distibines Me 2 Sb(CH 2 ) n SbMe 2 ( n = 6,10) are reported and compared with those of Me 2 As(CH 2 ) 12 AsMe 2 and the analogous ligands with C 2 and C 3 backbones.

Studies in Mössbauer spectroscopy. Part 10. Tin-119 spectra of compounds containing tin–cobalt bonds, and comments on the choice of partial-quadrupole-splitting values

Tin-119 Mossbauer data are reported for compounds of the type SnX4 –n[Co(CO)3(PR3)]n, (R = Ph or Bun: X = H. F. Cl, Br, or I : n= l–3). New partial-quadrupole-splitting (p.q.s.) values of –0.64(4) and –0.82(3) mm s–1 have been obtained for [Co(CO)4]– and [Co(CO)3(PR3)]–, and a value has been derived for the first time for the hydride ligand of –1.06 mm s–1. Apparent differences between various p.q.s. scales are discussed and shown to be illusory.