New Oxorhenium(V) Complexes from the Widely Used Diaminedithiol (DADT) Ligand System

Abstract

Synthesis of the 2,9-dimethyl-4,7-diaza-4-alkyl-2,9-decanedithiol (1, alkyl = morpholinylethyl in a, and alkyl = pyrrolidinylethyl in b), following a widely used synthetic scheme for diaminedithiol (DADT) ligands, led to the isolation of 1-alkyl-2-(1'-methyl-1'-sulfanylethyl)-3-(2' '-methyl-2' '-sulfanylpropyl)diazolidine (3) as the major product. Both ligands 1 and 2 gave complexes with the oxorhenium ReO(V) core. Ligand 1 gave the expected ReO[SNNS] complex (2) with the side chain on nitrogen in the syn configuration. Ligand 3 gave, in the presence of a monodentate aromatic thiol, complexes of the ReO[SNN][S][S] (4) and ReO[SNN][S] type (5), respectively, in which the diazolidine ring has rearranged to a thiazolidine ring. Crystallographic analysis showed that in 4 the coordination geometry about the metal is distorted octahedral where the equatorial plane is defined by the sulfur and one of the nitrogen atoms of the ligand and the two sulfurs of the aromatic thiols, while the axial positions are occupied by the oxygen of the ReO core and the second nitrogen of the ligand. Specifically, complex 4a crystallizes in space group P2(1)/c, a = 15.63(1) A, b = 15.28(2) A, c = 16.07(1) A, beta = 113.78(2) degrees, V = 3512(5) A(3), Z = 4. Complex 4b crystallizes in space group P2(1)/n, a = 14.560(9) A, b = 14.804(9) A, c = 19.85(1) A, beta = 90.94(2) degrees, V = 4278(1) A(3), Z = 4. In 5b, the coordination geometry is distorted square pyramidal with the SNN donor atom of the ligand and the aromatic thiol defining the equatorial plane and the doubly bonded oxygen occupying the apex of the pyramid. Complex 5b crystallizes in space group P(-)1, a = 9.387(5) A, b = 11.306(5) A, c = 14.040(6) A, alpha = 84.51(1) degrees, beta = 84.45(2) degrees, gamma = 87.17(1) degrees, V = 1475(1) A(3), Z = 2. All isolated complexes are neutral and lipophilic. Complete assignments of (1)H and (13)C NMR resonances are reported.

Stabilities of cubane type [Fe4S4(SR)4]2− clusters in partially aqueous media

“…Following related procedures [31,32], 2-ethylbutyr-aldehyde was converted to 2-ethyl-2-mercaptobutanol. To a solution of 0.31 g (2.27 mmol) of thiol in 5 mL of acetonitrile was added a solution of 0.48 g (0.49 mmol) of (Et 4 N) 2 [Fe 4 S 4 (SBu t ) 4 ] in 10 mL of acetonitrile.…”

Bifunctional chelators for radiorhenium: past, present and future outlook

“…While many of the BFCs for radiorhenium are based on the N 3 S ligand framework, the N 2 S 2 chelating system has also garnered considerable interest since it is able to form stable complexes with radiorhenium( v ). 83 This class of ligands includes bis(aminoethanethiols) (BAT), 84 monoamino-monoamidodithiols (MAMA) 85,86 and diamidodithiols (DADS), 83,87 some rhenium complex examples of which are shown in Fig. 7.…”

Oxidorhenium(V) and Rhenium(III) Complexes with Arylselenolato and ‐tellurolato Ligands

“…4 Among the ligands used for such applications, aromatic organochalcogenolates (ArE − with E=O, S, Se or Te) represent an interesting and versatile class [6–9] . The coordination chemistry of rhenium complexes containing organothiolato ligands is well known with thoroughly performed structural studies and well explored synthetic pathways [10–16] . In contrast, there is a substantial lack of studies with monodentate phenolates or with ligands coordinating through heavier chalcogen donor atoms.…”

“…[6][7][8][9] The coordination chemistry of rhenium complexes containing organothiolato ligands is well known with thoroughly performed structural studies and well explored synthetic pathways. [10][11][12][13][14][15][16] In contrast, there is a substantial lack of studies with monodentate phenolates or with ligands coordinating through heavier chalcogen donor atoms. Corresponding tellurium derivatives are especially scarce.…”