Crystal and molecular structure of tri-iodoheptakis(tri-p-fluorophenylphosphine)undecagold

Abstract

changes occur. I t also seems that the substitution of a chloride ion for a water molecule leaves the structure relatively unchanged. I t should be noted that all the structures should be known. Averaging of the 2-and I-hydrate energy changes gives an average enthalpy of reaction of 56.5 k J mol-l, close to what is observed for the vaporization of water. The entropy change appears to be more sensitive and should be the main criterion.Evidence indicates that the major change in structure occurs in the formation of the l-hydrate. The data are more compatible with a water molecule acting as a link between two adjacent CoI1 ions than with the replacement of a water molecule by a chloride ion, or the formation of chloride linkages with the remaining water molecule relegated t o the outer co-ordination sphere.The formation of anhydrous CoCl, is thus merely the exchange of a linking water molecule by a linking chloride ion.The distorted octahedral structure is retained by all the hydrates indicating the retention of structure and the favouring of a co-ordination number of six. The chloride linkage is favoured when the water is absent and is retained practically unchanged from the 2-hydrate to the anhydrous compound.W e thank Dr. S. D. Christian for discussions, Dr. H . W.

Phosphine-Coordinated Pure-Gold Clusters: Diverse Geometrical Structures and Unique Optical Properties/Responses

“…(31) (Fig. 1) [42], which is obviously different from the icosahedron-based structures with approximately C 3v symmetry found in the conventional Au 11 (PAr 3 ) 10 clusters for various combinations of phosphine, sub-ligands, and counter anion [28,29,33,47,65,84,88,99] (Table 1 and 23 and 30 in Fig. 1).…”

“…The borohydride reduction of monophosphine gold(I) complex (Au(PR 3 )X) in ethanol is the original recipe and has been most widely used as a conventional method, which generally yields Au 9 [27,37,38,61,62] or Au 11 species [19,[44][45][46][47][48][63][64][65]. NaBH 4 is commonly exploited as the reducing agent, because of the ease in handling.…”

“…Later, in 1970s and early 1980s, definitive X-ray structure determinations were achieved independently mainly by a Nijmegen group [20][21][22][23][24][25][26][27][28][29][30][31][32][33] and Mingos et al [34][35][36][37][38][39][40][41][42][43] for various PGCs with nuclearity of 5 -13 [44][45][46][47][48][49]. Most of these clusters exploited monodentate phosphines as the ligands, revealing the general trend of the geometrical preference in the formation of ultrasmall clusters under unconstrained conditions.…”

Redetermination of the structure of cyano(triphenylphoshine)gold(I)

“…Presumably the bulky PPh 3 groups determine the packing. An early structure from this series was that of the cyano derivative Ph3PAuCN (Bellon, Manassero & Sansoni, 1969). The structure was determined from photographic intensity measurements, which limited its precision; the bond lengths at gold were Au-P 2.27(1), Au--C 1.85(4)A, and the bond angle P-Au-C was 169 (2) °.…”

Aminkomplexe des Goldes, Teil 7: Pseudosymmetrie bei Aminkomplexen des Gold(I)-cyanids [1] / Amine Complexes of Gold, Part 7: Pseudosymmetry in Amine Complexes of Gold(I) Cyanide

“…B. Triethylphosphan [3], Triphenylphosphan [4,5], Methylisocyanid [6] oder Imidazol-2-ylidenen [7] gefunden werden. Alle diese Komplexe weisen wegen der d 10 -Konfiguration von Gold(I) dië ubliche lineare Form L-Au-CN auf.…”