Diversity in the Structural Chemistry of (Phosphine)gold(I) 1,3,4-Thiadiazole-2,5-dithiolates (Bismuthiolates I)

Abstract

A series of dinuclear (phosphine)gold(I) complexes of the ambidentate 1,3,4-thiadiazoledithiolate ligand (SSS) were prepared in high yield from the corresponding (phosphine)gold(I) chlorides and K(2)(SSS) in methanol. While mononuclear components (R(3)P)AuCl with R(3) = Ph(3), Ph(2)Py, or Me(3) (1-3) gave open-chain complexes, the dinuclear components ClAu(Ph(2)P-E-PPh(2))AuCl with E = (CH(2))(6), (C(5)H(4))Fe(C(5)H(4)), or 1,4-CH(2)C(6)H(4)CH(2) afforded cyclic complexes (4-6). The products have been characterized by analytical and spectroscopic methods, and the crystal structures of 1-4 have been determined by single-crystal X-ray techniques. Crystals of 1 [(CH(2)Cl(2))(2)] and 2 (CH(2)Cl(2)) contain the molecules aggregated in strings with long and probably very weak intermolecular Au.S contacts. The P-Au-S groups are aligned parallel head-to-tail and shifted in opposite directions to reduce steric conflicts, thus ruling out aurophilic Au...Au bonding. By contrast, in crystals of 3 (CH(2)Cl(2)) with smaller tertiary phosphine ligands, the molecules are aggregated via short [3.0089(3) and 3.1048(5) A] and probably strong aurophilic bonding to give a two-dimensional network with tetranuclear units formed from four (Me(3)P)AuS moieties of four different molecules as the connecting elements. In these tetranuclear units [(Me(3)P)AuS-](4), the P-Au-S axes are rotated against each other ("crossed swords") by 108.5 degrees (P2-Au2...Au2'-P2') or 116.9 degrees (P2-Au2...Au1'-P1'), respectively, to minimize steric conflicts. There is also significant bending of the P-Au-S axes to bring the metal atoms closer together: P1-Au1-S1 = 171.88(8) degrees and P2-Au2-S2 = 165.52(8) degrees. In the crystals of the cyclic complex 4 which contain no solvent molecules, the molecular units are aggregated in strings with short closed-shell interactions between the gold atoms of neighboring molecules [3.1898(3) A]. Because of the metallocyclic structure, the shielding of the gold atoms is reduced to allow aurophilic bonding as the P-Au-S groups are rotated against each other (crossed) by a dihedral angle P-Au...Au-P of 74.6 degrees.

Predictive Gold Nanocluster Formation Controlled by Metal‐Ligand Complexes

“…Specifically, evidence for aurophilic interactions are reported in the bridged Au I :L 1 systems, where the relative strength of the aurophilic interactions can be affected by solvent contributions and other complexing ligands 35, 36. Schmidbaur and co‐workers37 have also suggested that increased flexibility of phosphine ligands can promote aurophilic interactions, indicating that the relative contributions of aurophilic interactions in the Class I and Class II ligands are likely different. The observed difference in reduction efficiencies of the predominant complexes between classes could also be affected by aurophilic contributions.…”

Monodentate and bridging coordination of 2,5-dimercapto-1,3,4-thiadiazolate to a (2,2′:6′,2″-terpyridine)platinum(ii) center

“…The complexes whose structures are reported include one ruthenium, 22 one mercury, 20 one thallium 21 and gold complexes. 23, 24 The thallium complex is not a discrete complex but a solid state polymer constructed mainly of ionic interactions between {Tl(Me) 2 } ϩ and DMcT 2Ϫ (Tl ؒ ؒ ؒ S > 3.2 Å, Tl ؒ ؒ ؒ N > 2.7 Å), and DMcT 2Ϫ may be regarded as a counter anion rather than a ligand. The mercury, gold and ruthenium complexes are molecular complexes, in which the DMcT 2Ϫ ligand coordinates to the metal center via the thiolate sulfur atoms.…”

Exploration on Au(S–4-py)PR3 complexes as a viable building block for constructing hetero-nuclear supramolecules: synthesis and X-ray study on M(acac′)2[Au(S–4-py)PR3]2(ClO4) (M = Cr, Cu; acac′ = acetylacetonate, hexafluoro-acetylacetonate; x= 0 or 1)

“…First, these ligands have a potential coordinating ability to other transition metal(s) through the pyridine-N atom in order to construct new supra molecules such as ''molecular-dots'' and/or ''molecular-wires'' (Scheme 1) by virtue of the strong interaction [12,13]. Second, the S atom sometimes works as a multidendate coordinating site to yield sophisticated supra structures in addition to induce and/or strengthening aurophilicity [14][15][16]. Another interesting examples were reported previously by Che and Puddephat for (LAu) 3 (S 3 C 3 N 3 ), which loses two ligand groups L in solution and dimerized to give a hexamer, Au 6 L 4 (S 3 C 3 N 3 ) [17,18].…”