Dinuclear gold(I) dithiophosphonate complexes:: Synthesis, luminescent properties, and X-ray crystal structures of [AuS2PR(OR′)]2 (R = Ph, R′ = C5H9; R=4-C6H4OMe, R′ = (1S,5R,2S)-(-)-menthyl; R = Fc, R′ = (CH2)2O(CH2)2OMe)

2,4-Diaryl- and 2,4-diferrocenyl-1,3-dithiadiphosphetane disulfide dimers (RP(S)S)(2) (R = Ph (1a), 4-C6H4OMe (1b), FeC10H9 (Fc) (1c)) react with a variety of alcohols, silanols, and trialkylsilyl alcohols to form new dithiophosphonic acids in a facile manner. Their corresponding salts react with chlorogold(I) complexes in THF to produce dinuclear gold(l) dithiophosphonate complexes of the type [AuS2PR(OR')](2) in satisfactory yield. The asymmetrical nature of the ligands allows for the gold complexes to form two isomers (cis and trans) as verified by solution H-1 and P-31{H-1} NMR studies. The X-ray crystal structures of [AuS2PR(OR')](2) (R = Ph, R' = C5H9 (2); R = 4-C6H4OMe, R' = (1S,5R,2S)-(-)-menthyl (3); R = Fc, R' = (CH2)(2)O(CH2)(2)OMe (4)) have been determined. In all cases only the trans isomer is obtained, consistent with solid state P-31 NMR data obtained for the bulk powder of 3. Crystallographic data for 2 (213 K): orthorhombic, Ibam, a = 12.434(5) Angstrom, b = 19.029(9) Angstrom, c = 11.760(4) Angstrom, v 2782(2) Angstrom(3), Z = 4. Data for 3 (293 K): monoclinic, P2(1), a = 7.288(2) Angstrom, b = 12.676(3) Angstrom, c = 21.826(4) Angstrom, beta = 92.04(3)degrees, V = 2015.0(7) Angstrom(3), Z = 2. Data for 4 (213 K): monoclinic, P2(1)/n, a = 11.8564(7) Angstrom, b = 22.483(1) Angstrom, c = 27.840(2) Angstrom, beta = 91.121(1)degrees, V = 7419.8(8) Angstrom(3), Z = 8. Moreover, 1 a-c react with [Au-2(dppm)Cl-2] to form new heterobridged trithiophosphonate complexes of the type [Au-2(dppm)(S2P(S)R)] (R = Fc (12)). The luminescence properties of several structurally characterized complexes have been investigated. Each of the title compounds luminesces at 77 K. The results indicate that the nature of (AuAu)-Au-... interactions in the solid state has a profound influence on the optical properties of these complexes.