Google
 

Synthesis and X-ray Structural Study on the Complexes of Silver(I) Halide with Tricyclohexylephosphine,....

>

Diphenyl(
2,4,6- trimethoxy)phenylphosphine, Phenyl-2,4,6trimethoxyphenyl
phosphine, and Tris(2,4,6-
trim ethoxy)phenylphosphine. A diverse array of structures for the complexes of silver(I) halide with triphenylphosphine (PPh3) has been
studied. The complexes may be described as being of the type [AgX(PPh3)n] (X = Cl, Br or I). The value of n varies in
the range of 1-3. This also indicates that the stoichiometry of the complexes is in the range of 1-3. The complex with
stoichiometry 1:1 is a tetramer. There are two structural types of tetramer reported, termed cubane and step or chair. The
cubane structure has been reported for [AgX(pPh3)]4ex = Cl, Br or I), while the step structure has only been reported for
[AgI(PPh3)]4' The complex with stoichiometry 1:2 may be a monomer or a dimer. The monomer has a quasi trigonal
planar structural type and has only been reported for [AgBr(PPh3)2l The dimer has been reported for [(PPh3)2Ag(J.!­X)
2Ag(PPh3)2](X = Cl or Br) with silver atom in the distorted tetrahedral environment. The complex with stoichiometry
1:3 has a distorted tetrahedral structural type and has been reported for [AgX(PPh3)3](X = Cl, Br or I). Changing PPh3
with more hindered ligand such as tricyclohexylephosphine (PCY3)or derivative of PPh3 such as diphenyl-2,4,6trimethoxy(
phenyl)phosphine (dpmp), phenyl-bis{2,4,6-trimethoxy(phenyl)} phosphine (pdmp), or tris{2,4,6trimethoxy(
phenyl)}phosphine (tmpp) may give complexes with various structural types but with lower range of
stoichiometry. Synthesis and X-ray structural study of these complexes has been done with the results summarized
below. Silver(I) halide and PCY3give complexes with stoichiometry 1:1 and 1:2. The complex with stoichiometry 1:1 is
a dimer or cubane. The dimer is observed for [(PcY3)Ag(J.!-X)2Ag(PCY3)] ex = Cl or Br). The unusual dimer is observed
for [(PcY3)Ag(J.!-IMJ.!-py)Ag(PCY3)] where the pyridine ligand is bonded to two silver atoms. The cubane is observed for
[AgI(PCY3)J4,The complex with stoichiometry 1:2 has a quasi trigonal planar structural type and has been observed for
[AgX(PCY3)2]ex = Cl, Br, I). Silver(I) halide and dpmp give complexes with stoichiometry 1:1 and 1:2. The complex
with stoichiometry 1:1 is a dimer and has been observed for [(dpmp)Ag(J.!-X)2Ag(dpmp)]ex = Cl, Br or I). The complex
with stoichiometry 1:2 has a quasi trigonal planar structural type and has been observed for [AgX(dpmp)2] (X = Cl, Br,
I). Silver(I) halide and pdmp also give complexes with stoichiometry 1:1 and 1:2. The complex with stoichiometry 1:1 is
a dimer and has been observed for [(pdmp)Ag(J.!-X)2Ag(pdmp)](X = CI, Br or I). The complex with stoichiometry 1:2
has a quasi trigonal planar structural type and has been observed for [AgX(pdmp)2] (X = CI, Br, I). Silver(I) halide and
tmmp only give complexes with stoichiometry I: I. This complex is a monomer and has been observed for [AgX(tmpp)]
(X = Cl or Br). In this complex the silver atom is in a quasi linear environment. Based on the bond lengths between
silver and phosphorous atoms in the complexes obtained, it can be concluded that bulky ligands tend to give complexes
with lower range of stoichiometry. In addition, the bulkier the ligand the longer the bond length between the silver and
phosphorous atoms. Effendy1 and A. H. White2
/ Jurusan Kimia, FMIPA Universitas Negeri Malang, Jl. Surabaya 6Malang 65145, Indonesia
2 Chemistry, School of Biomedical, Biomolecular, and Chemical Sciences, The University of Western
Australia, 35 Stirling Highway, Crawley WA 6009, Australia