
%0 Journal Article
%A Bennett, MA 
%A Fick, HG 
%A Warnock, GF 
%T Cyclohexyneplatinum(0) Complexes Containing Di-t-butylphenylphosphine, t-butyldiphenylphosphine or Trimethylphosphine
%J Australian Journal of Chemistry
%D 1992/01/01
%V 45
%N 1
%P 135-142
%K 
%R https://doi.org/10.1071/CH9920135
%U https://www.publish.csiro.au/paper/CH9920135 
%X Cyclohexyneplatinum (0) complexes Pt(C6H8)L2 [L = PBut2Ph(4), PbutPh2(5)] analogous to the known complex (3) (L=PPh3) have been prepared by reaction of the two-coordinate complexes PtL2 with 1,2-dibromocyclohexene and 1% sodium amalgam. The corresponding tricyclohexylphosphine complex is formed by a similar reaction but it could not be isolated in a pure state. Attempts to prepare analogues of (4) and (5) containing cycloheptyne or cyclooctyne were unsuccessful, possibly because the bulky t-butyl groups of the tertiary phosphines hinder coordination of the larger rings. Bulky tertiary phosphines do not displace PPh3 from (3) but trimethylphosphine reacts with (3) to give successively Pt(C6H8)(PMe3)2(PPh3) (10) and Pt(C6H8)(PMe3)2 (11), as shown by 31P{1H) n.m.r. spectroscopy. The tertiary phosphines in these complexes equilibrate rapidly at room temperature in benzene and only (10) can be isolated as a solid from the reaction. Complexes (4) and (5) react with HCl (1 molar proportion) to give n1-cyclohexen-l-yl complexes trans- PtCl (C6H9)L2 [L= PBut2Ph(6), PButPh2 (7)]. In the absence of air, (4) reacts with methanol at 65&#176;C to give the hydrido complex trans- PtH (C6H9)(PBut2Ph)2 (8). In the presence of oxygen from the air, however, the main product is the dioxygen complex Pt(O2)(Pbut2Ph)2 (9). This represents an unusual example of complete displacement of cyclohexyne from a platinum(0) complex by a &#960;-acceptor ligand. 
