Cyclic dinuclear gold(I) complexes: The crystal structure of bis‐μ‐[(diphenylphosphino)(diphenylphosphinoselenoyl)methane]‐digold(I) bis(perchlorate)

Abstract

[(CO)AuCl] reacts with equimolar amounts of PhzPCH,P(Se)Ph2 (dpniSe) to afford CIAuPhzPCHzP(Se)Phz, in which dpmSe is bound to gold in a monodentate fashion by phosphorus. Subsequent reaction of this 1: 1 complex with AgC104 results in the formation of the 10-membered ring complex 4 which crystallizes in the monoclinic space group E1/n with approximately centrosymmetric dicationic units, in which two gold(1) atoms are doubly bridged by two dpmSe ligands coordinated by phosphorus and selenium. The coordination at the gold atoms deviates from linearity and implies an Au-.Au interaction with the gold(1) atoms separated by a distance of 3.020(1) A.As evidenced by the number of review articles and monographs published in recent years 1-6), inorganic and organometallic chemistry of gold is an ever expanding area of research. For the purpose of promoting metal nucleation, which is important, for example, in the controlled deposition of gold in micro-electronics and electron microscopy, extensive studies habe been undertaken on dinuclear gold@) complexes. Initial studies focused on 1,3-difunctional ligands, and several compounds with the 8-membered ring structure 1 have been synthesized. Short transannular Au-.Au contacts are observed in all of these complexes. Weak bonding appears to be operative perpendicular to the linear X-Au-X' axes and can be described as a 5d1"-5d" interaction based on a mixing with the 6s orbitals19), whose energy is lowered by relativistic effects", 'l). Many authors, however, have suggested that there are no significant bonding interactions involved as short Au-Au distances are perhaps not surprising for gold atoms constrained by ring geometry and the small bite of the 1,3-difunctional ligands. The frequency of occurrence of short Au -Au distances in various other types of complexes, however, is not consistent with this view.Clearly, the fixation of metal atoms in close geometrical proximity becomes less favourable as the number of atoms separating the ligand donor atoms increases. A recent report2') has provided evidence for the existence of an attractive interaction between gold(1) centres based on changes in the conformation of the butadiene skeleton. The s-trans ground state geometry of 2,3-bis(diphenylphosphino)-1,3-butadiene is abandoned upon double complexation with AuCl, and the two gold atoms are brought into contact at a distance of 3.023(1) A. If it is assumed that the s-trans to s-cis reorientation is caused by Au...Au attraction, the bond energy is estimated to be in the order of 7 kcal/mol. This result is in good agreement with that arrived at for the analogous system with the 1,4-difunctional ligand 1,l'-bis(dipheny1phosphino)bicyclopropyIz3). In the 10-membered ring complex [ A U~( S C H~C H~P E~~)~] the S-Au-P angle of 173.5" is also adduced as evidence for a Au...Au interaction") since the deviation from linearity is such as to bring the metal atoms closer together.In an effort to further investigate the influence of the weak attractive force between closed-shell (d"-d") centr...

Bis(diphenylphosphino)methane and related ligands as hydrogen bond donors†

“…1 and 2). The structure of a two-coordinate gold(i) complex of the same ligand has been reported by Schmidbaur, et al 9 and by chance belongs to the set of 23 compounds discussed above; it displays two C-H•••O acetone hydrogen bonds.…”

Chalcogen Capture by an Al/P-Based Frustrated Lewis Pair: Formation of Al-E-P Bridges and Intermolecular Tellurium–Tellurium Interactions

“…P–E bond lengths of chalcogentriaryl- or -trialkylphosphorus­(V) compounds R 3 PE ,,, are about 0.08 Å (E = S, Se) or 0.10 Å (E = Te) shorter than those in 2 or related compounds, such as [(H 5 C 6 ) 2 ­P­(S-AlMe 3 )­CH 2 ] 2 (1.989(2) Å), (H 5 C 6 ) 3 ­PSeAuBr (2.207 Å), or ( i Pr 3 PTe) 4 ­Ag 2 [N­(SO 2 Me) 2 ] 2 (2.400 Å), − in which the chalcogen atom acts as electron donor toward a metal atom. The latter compound and 2c are currently the only crystallographically characterized phosphine-tellurides of this type with a two-coordinate Te atom.…”

Synthesis and Characterization of Thienyl Oligomeric, Carbene, and Nitrogen-Donor Complexes of Gold(I)

“…Some structural information on binuclear complexes related to complex 1 are collected in Figure 2. It is evident that this type of ring twisting occurs in compounds A, 6 B, 33 and D 34 (Figure 2) with dihedral angles of 64.8(4)°, 48.12(6)°, and 15.61(3)°, respectively. In compound D (Figure 2), 34 the two rings are twisted even though no cyclic strain is evident.…”