The dynamics of spin-lattice relaxation (slr) of metal-organic Pt(II)
compounds is studied. Often, such systems are characterized by pronounced
zero-field splittings (zfs) of the lowest-lying triplets. Previous expressions
for the Orbach slr process do not allow to treat such splitting patterns
properly. We discuss the behavior of a modified Orbach expression for a model
system and present results of a fit of the temperature dependence of the
spin-lattice relaxation rate of Pt(2-thpy)2 based on the modified
expression.Comment: 9 pages, 3 figures (made from 4 .eps files), elsart.cls. Using dvips
(dvipsk 5.58f), it may be necessary to manually edit the generated file
letter.ps to change in the first line from PS-Adobe-2.0 to PS-Adobe-3.0.
Chemical Physics Letters, in pres