Reaction of mercury(II) diiodide with triphenyl selenophosphorane-Se (1:1 mole ratio) in acetone followed by recrystallisation of the product from chloroform formed crystals of stoichiometry HgI₂(Ph₃PSe)(1). Compound1 exists as a centrosymmetric homobimetallic dimer, Hg(Μ-I)I(Ph₃PSe)₂, as monoclinic crystals of space group P2₁/n. The dimer comprises two Μ₂-iodo atoms that form unequal Hg-I bonds 2.8230(10), 3.1135(9) å and two equal terminal Hg-I bonds 2.6524(10) å. The Se atom of Ph₃PSe forms terminal Hg-Se bond 2.5914(11)å and thus the geometry about each Hg centre is distorted tetrahedral and the range of tetrahedral bond angles is 92.97(2) to 130.85(3)‡, the largest being that of Se(1)-Hg(1)-I(1) and the shortest, I(2)-Hg(1)-I(2)‡. Hg-Hg and I-I separations of 4.0930(11)å and 4.3097(15)å are more than the sums of their respective van der Waal radii 3.00 å and 4.24 å.

Thiophene-2-carbaldehyde / acetaldehyde-N¹-substituted thiosemicarbazones {R¹R²C² = N³ - N(H)- C¹(=S)N¹HR; R¹, R², R : C₄H₃S, H, Me, Httsc- NMe; C₄H₃S, H, Et, Httsc-NEt; C₄H₃S, H, Ph, Httsc-NPh; C₄H₃S, Me, Et, Hattsc-NEt} and furan-2-carbaldehyde-N-ethyl thiosemicarbazone (C₄H₃O, H, Et, Hftsc-NEt) were reacted with silver(I) halides/silver(I) acetate in presence of triphenylphosphine in organic solvents. These reactions yielded a series of dinuclear [Ag₂(μ-Br)₂ (κ-S-Httsc-NEt)2(PPh3)2]·2MeOH 1, [Ag2Cl2(κ1-SHttsc-NPh)2(μ-S,S-Httsc-NPh)2] 2, [Ag2Cl2(μ-S-Hftsc-NEt)2(κ1-S-Hftsc-NEt)2] 4, [Ag2(μ3-N3,S-ttsc-NMe)2 (Ph3P)2]·2(CH3)2CO 5, [Ag2 (μ3-N3,S-attsc-NEt)2(Ph3P)2]·0.5(CH3)2CO 6 and mononuclear [AgBr(κ1-SHttsc-NPh)(PPh3)2]· MeCN 3 complexes, all of which have been characterized using analytical techniques, IRand NMR spectroscopy, and X-ray crystallography. Thio-ligands bind in neutral form in complexes 1-4 and in anionic form in complexes 5-6. Further, the sulfur donor atoms have shown variable coordination modes incomplexes, namely, κ1-S in 1 and 3; κ1-S, μ-S in 4; κ1-S, μ-S,S (thiopheneyl-thione) in 2 and μ3- N3, S in 5 and 6. Tertiary-phosphine (PPh3) showed dual function of ligation/de-ligation towards silver(I) chloride during the synthesis of complexes 2 and 4. The bridge bonding of Httsc-NPh in 2 through thiopheneyl ring sulfur andthione sulfur is unprecedented in metal-thiosemicarbazone chemistry.

Reaction of [PdCl ₂ (PPh ₃) ₂] with imidazolidine-2-thione {SC₃H₄ (NH) ₂} in the presence of triethylamineinvolved activation of N–H bonds and formed an unusual oxo-bridged dianion, (SC ₃H ₄N ₄–O–N ₂C ₃H ₄S) ² ⁻ coordinated to Pd^II in [Pd{κ ³–S, O,S–(SC ₃H ₄N ₂–O–N ₂C ₃H ₄S)}(PPh₃)]•CH₃CN 1, which hasbeen studied using elemental analysis, IR, NMR, X-ray crystallography and ESI-mass studies.