75180-86-8Relevant academic research and scientific papers
Preparation and NMR characterization of η1-N-bonded platinum-(II) and palladium(II) adducts of eight-membered heterocyclic thiazenes
Chivers, Tristram,Hilts, Robert W.
, p. 5272 - 5279 (2008/10/08)
The reaction of the diphosphadithiatetrazocines 1,5-R4P2N4S2 with [MCl2(PEt3)]2 (M = Pt, Pd) in a 2:1 molar ratio in CH2Cl2 or THF at 23°C produces the 1:1 adducts trans-[MCl2(PEt3)(R4P2N 4S2)] (5c, M = Pt, R = Ph; 5d, M = Pt, R = Et; 5e, M = Pt, R = Me; 5f, M = Pd, R = Et; 5g, M = Pd, R = Me) in which the P2N4S2 ligand is bound to either palladium or platinum via nitrogen. The dithiatetrazocine, 1,5-(Me2NC)2N4S2, and the trithiatetrazocine, PhCN4S3NPPh3, react with [PtCl2(PEt3)2]2 to give the adducts PtCl2(PEt3)[(Me2NC)2N 4S2] (6) and PtCl2(PEt3)(PhCN4S3NPPh3) (9), respectively. The adduct 6 is obtained as a mixture of isomers, according to 1H and 31P NMR spectroscopic data, in which the platinum atom is bonded to either an exocyclic or an endocyclic nitrogen atom, 6a and 6b, respectively. Variable-temperature 1H and 31P NMR studies show that 6a is converted into 6b and indicate that the PtCl2(PEt3) group is involved in a ring-whizzing process via a series of 1,3-shifts at higher temperatures. The adduct 9 is obtained as a single isomer in which the platinum atom is probably attached to an endocyclic nitrogen geminal to the NPPh3 group. The heterocyclic ligands in 5c and 6 are readily displaced by THF to give trans-[PtCl2(PEt3)(η1-O-THF)] (8). In contrast, the adducts 5d and 5e do not dissociate in THF solution. The reaction of Pt(CH2=CH2)(PPh3)2 with the N-bonded adducts [Et4P2N4S2Me] [CF3SO3], 5d or 5e, in toluene at 0°C produces the complexes Pt(PPh3)2(R4P2N4S 2E) (10a, R = Et, E = Me+; 10b, R = Et, E = PtCl2(PEt3); 10c, R = Me, E = PtCl2(PEt3)) in good yield. The 31P NMR spectrum of 10a indicates that the Et4P2N4S2Me+ ligand is bonded to platinum in a η2-S,S′ mode, while the 31P NMR spectra of the bimetallic complexes 10b and 10c are consistent with structures in which the R4P2N4S2 ligand is η1-N-bonded to one platinum and η2-S,S′-bonded to the other platinum atom. The decomposition of 10b in THF at 23°C produces PtCl2-(PEt3)(PPh3) and the bimetallic dimer [Pt(PPh3)(Et4P2N4S 2)]2. The reaction of equimolar amounts 1,5-R4P2N4S2 (R = Et, Ph) with [PtCl2(PEt3)]2 in CH2Cl2 produces 2:1 and 3:1 η1-N-bonded platinum(II) adducts, in addition to 5c, on the basis of 31P NMR spectroscopy.
SOME CHEMISTRY OF MIXED LIGAND COMPLEXES OF PLATINUM
Clark, Howard C.,Goel, Anil B.,Wong, Chun S.
, p. C101 - C104 (2007/10/02)
Simple synthetic routes to the mixed ligand complexes PtLL'X2 and PtLL'XY (L' = PEt3; L = phosphine, arsine, etc.; X = Cl and Y = Cl, H or Me) are described; unexpectedly, these display an extensive chemistry without disproportionation, although in some c
