ISSN:
0009-2940
Keywords:
Labile ruthenium-sulfur complexes
;
S2 Complexes
;
Substitution reactions
;
Ligand effects
;
Structure-activity relationships
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In order to synthesize labile and well-soluble [Ru(L)(L')(“S4”)] complexes, [Ru(CI)2(DMSO)4] was treated With “S4”-Na2 (S42- = 1,2-bis(2-mercaptophenylthio)-ethane(2-1)] yielding [Ru(DMSO)2(“S4”)] (1 which contains two labile DMSO ligands. An X-ray structural analysis of 1, verifies that both DMSO ligands are coordinated via their S atoms. The reaction of 1 with small ligands such as PR3 (R = Et, nPr, nBu) or tetrahydrothiophene (THT) leads to substitution of both DMSO ligands yielding [Ru(PR3)2(“S4”)] (R = Et 3a, nPr 3b, nBu 3c) and [Ru(THT)2(“S4”] 2, respectively, while bulky phosphane ligands such as PCy3 and PiPr3 substitute one DMSO ligand to yield [Ru(DMSO)(PR3])(“S4”] (R = iPr 4a, Cy 4b). X-ray structural analyses of [Ru(PnPr3)2(“S4”)] · 0.5 MeOH (3b · 0.5 MeOH), [Ru(PnBu3)2(S4)} (3c), and [Ru(Pme3)2(“S4”)] (3d) confirm the pseudo-octahedral coordination of the Ru centers by four Sdonors and two cis P-donors and reveal close similarities bet ween the three complexes. Comparision of the structural parameters of 3b · 0.5 MeOH, 3c and 3d with those of [Ru(PPh3)2(“MeS, 4”)] [MeS4“2” = 1,2-bis(2-mercaptophenylthio)propane(2-1)] indicates that the inertness towards substitution of 3b · 0.5 MeOH, 3c and 3d as opposed to the substitution lability of [Ru(PPh3)2(,MeS4“)] is caused by the small cone angles of the alkyl phosphanes. In the DMSO/PCy3 complex 4b both coligands are labile, and which one is substituted depends on the size of the entering ligand. The reactions of 4b with PnR3 yield [Ru(DMSO)(PR3)('S4”)] (R = nPr 4c, nBu 4d) in contrast to the reaction with CO. PMe3, and SMe2 which give [Ru(CO)(Pcy3)(“S4”)] (5b), [Ru(P-Me3)(PCy3)(“S4”)] (6, and [Ru(SMe2)(PCy3)(“S4”)] (7, respectively. In an analogous manner, the CO complexes [Ru(CO(PR3)(“S4”)] (R = iPr 5a, nBu 5c) have been obtained by treatement of 4a and 4d with CO. The reactions of 4a and 4b with S8 yielded the readily soluble μ-S2 complexes [μ-S2[Ru(PR3)(“S4”)]2] (R - iPr 8a, Cy 8b). The spectroscopi9c data of complex 8b and its cyclic voltammogram, which exhibits four quasi-reversible redox waves, indicate a strong electronic coupling of the two [Ru(PCy3)(“S4”)] fragments via the μ-S2 bridge.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19971300507
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