J. Depriest et al., STRUCTURE, PHYSICAL AND PHOTOPHYSICAL PROPERTIES OF PLATINUM(II) COMPLEXES CONTAINING 7,8-BENZOQUINOLINE AND VARIOUS BIS(DIPHENYLPHOSPHINE)LIGANDS, Inorganica Chimica Acta, 264(1-2), 1997, pp. 287-296
A series of platinum complexes, [Pt(7,8-bzq)(dppm)](PF6), [Pt(7,8-bzq)
(dppe)](PF6) and [Pt(7,8-bzy)(dppp)](PF6), which vary only in the numb
er of carbon atoms bridging two diphenyl phosphine ligands, have been
synthesized and their structures have been determined by single crysta
l X-ray crystallography. Structural characteristics are as follows: [P
t(7,8-bzq)(dppm)](PF6), orthorhombic, Pbca, a = 17.427(4), b = 17.946(
4), c = 22.262 Angstrom, Z = 8; [Pt(7,8-bzq)(dppe)](PF6), monoclinic,
P2(1)/c, a = 11.519(2), b = 14.080(3), c = 21.804(4) Angstrom, Z = 4;
[Pt(7,8-bzq)(dppp)](PFepsilon), Pna2(1), a = 20.216(4), b = 11.574(2),
c = 15.739(3) Angstrom, Z = 4. The P-Pt-P bite angle varies in the se
ries from 72.1(5) to 84.5(2) to 91.57(10)degrees for [Pt(7,8-bzq)(dppm
)](+), [Pt(7,8-bzq)(dppe)](+) and [Pt(7,8-bzq)(dppp)](+), respectively
. The absorption spectra are blue-shifted and the emission lifetimes a
t 77 K increase in the same order. Emission lifetime differences are s
hown to relate to the perturbation associated with the additional meth
ylene groups. (C) 1997 Elsevier Science S.A.