
%0 Journal Article
%A Whittall, Ian R. 
%A Humphrey, Mark G. 
%A Hockless, David C. R. 
%T Structural Systematics of Metal Acetylide Complexes: X-Ray Studies of Some 'Extended-Chain' Gold &sigma;-Acetylide Complexes
%J Australian Journal of Chemistry
%D 1997/12/15
%V 50
%N 10
%P 991-998
%K 
%R https://doi.org/10.1071/C97049
%U https://www.publish.csiro.au/paper/C97049 
%X The structures of Au(4-C&#8801;CC6H4XYC6H4-4&#8242;-NO2)(PPh3) (XY = (E )-CH=CH (1), (Z)-CH=CH (2), C&#8801;C (3), N=CH (4)) have been determined by single-crystal X-ray diffraction analyses, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a8&#183;847(1), b 17&#183;870(4), c 19&#183;705(3) &#197;, &#945;116&#183;25(1), &#946; 93&#183;33(1), &#947; 92&#183;64(2)&#x02DA;, Z 4, 6747 unique reflections (703 parameters), converging at R 0&#183;025 and Rw 0&#183;029. For (2), crystals are monoclinic, space group P 21/a, with a 10&#183;718(6), b 19&#183;398(5), c14&#183;469(3) &#197;, &#946; 108&#183;96(2)&#x02DA;, Z 4, 3295 unique reflections (352 parameters), converging atR 0&#183;040 and Rw 0&#183;034. For (3), crystals are triclinic, space group P-1, with a 10&#183;671(4), b 17&#183;599(7), c 18&#183;220(8) &#197;, &#945; 116&#183;31(3), &#946; 105&#183;00(4), &#947; 95&#183;08(4)&#x02DA;, Z 4, 4828 unique reflections (703 parameters), converging at R 0&#183;043 and Rw 0&#183;030. For (4), crystals are triclinic, space group P-1, with a 8&#183;8314(6), b 17&#183;834(2), c 20&#183;001(2) &#197;, &#945; 115&#183;249(7), &#946; 90&#183;930(7), &#947; 94&#183;082(7)&#x02DA;, Z 4, 4724 unique reflections (703 parameters), converging at R 0&#183;035 and Rw 0&#183;034. Despite the &#91;ligated metal donor&#93;-bridge-&#91;nitro acceptor&#93; composition of these complexes, Au&#8211;C and C&#8801;C distances are normal and consistent with minimal allenylidene contribution to the ground-state geometry. Within the 3&#963; confidence limits, the structural data do not provide evidence for &#960;*-back-bonding in these complexes 
