Abstract
The reaction of mercury(II) chloride with neutral phosphine telluride ligands (R
3
PTe) produced new mercury(II) complexes, HgCl
2
(R
3
PTe)
2
[R = Me
2
N (1), Et
2
N (2), C
4
H
8
N (3), C
5
H
10
N (4) or
n-
Bu (5)]. Attempts to isolate the complex of HgCl
2
with the morpholinyl ligand, (OC
4
H
8
N)
3
PTe, were unsuccessful. Complexes 1-5 have been characterized by elemental analyses, IR, and multinuclear (
31
P,
125
Te, and
199
Hg) NMR spectroscopy. The solution behavior of the complexes was investigated using variable temperature NMR spectroscopy in the presence of excess ligand and indicated fast ligand exchange on the NMR timescale at room temperature. The metal-ligand exchange barriers in these complexes were estimated to be in the range 8-11 kcal/mol. The results suggest that a slight change in the nature of the substituents on the phosphorus of the ligand can contribute considerably to the lability of the complex obtained. The NMR data are discussed and compared with those obtained for related phosphine chalcogenide systems.