Five Co-ordinate Complexes of Platinum(II) and Palladium(II)

Abstract

[Traduit par le journal]Can J Chern , 5 1 , 618 (1973)

The Crystal Structure of cis-Chlorobis(triethylphosphine)-1,10-phenanthrolineplatinum(II) fluoroborate, (PtCl(PEt3)2(phen))BF4, a Complex Containing Monodentate 1,10-Phenanthroline

“…A COLITtaulds model could not be built and we would predict severe intra-ionic repulsion. When the title compound is refluxed in methanol there is a reaction, the first step of which is presumed to be phosphine dissociation, with the chlorine ligand remaining coordinated (8). Thus there appears to be no tendency toward the alternative scheme, and some support for our steric reasoning.…”

“…The preparation and characterization of the complex have already been described (8). 'H nuclear magnetic absences.…”

“…141.1 (27) C (21) Since a five-coordinate (trigonal bipyramidal) structure was assigned previously (8) --*.r, y, and r a r e the coordinates in prn along the orthogonal axis system, defined as x along a , y in the (a,b) plane, and r a l o n g c*.…”

“…Here the evidence is that chlorine is coordinated (conductance), that the two PEt, groups a r e chemically inequivalent ( species but the width of the range makes a positive the complex is five-coordinate and trigonal bipyramidal, (b) that in solution the complex is four-coordinate with a monodentate phen rapidly exchanging its point of attachment between N(l) and N(2), (c) that the complex contains monodentate phenanthroline as in the solid state but the electronic difference between the coordinated and non-coordinated rings is too small to be detected by ' H magnetic resonance spectroscopy. The last possibility may be rejected since we were previously able to distinguish easily between the two halvks of a coordinated phenanthroline in which the nitrogen atoms were trans t o phosphorus and chlorine respectively in the [PtCI-(phen)(PEt3)]+ cation (8). The electronic asymmetry produced by different trans influences would be much smaller than that produced by coordination or non-coordination.…”

“…The existence of five coordinate resonance spectra were recorded at 40.5 MHz in dichlorocomplexes of platinum(I1) has also been reported methane solution using H , P o 4 as external reference on on the basis of spectroscopic (2)(3)(4)(5) and X-ray a Varian XL-100 spectrometer with noise decoupling of diffraction (6-7) studies. In view of the rarity of P r~t O s~; e s of Weisanberg and Precession photographs five coordinate platinun~ complexes cveconsidered obtained using ~~~~~~d i~ ~h~ space group it of interest to undertake a crystal structure study P2,/c was established unequivocally from the systematic of (PtCl(phen)(PEt,),)(BF,), since conductance and proton magnetic resonance studies had suggested a five-coordinate structure as the most likely for this complex in solution (8). However, the X-ray results for the solid show a very unusual structure with essentially monodentate phenanthroline.…”