Organomercury compounds. VII. Complexes of arylmercuric halides with bidentate ligands

The complexes, C6F5HgXL2 [X = Br or C1; L2 = 2,2'-bipyridyl (bipy), 1,l0-phenanthroline (phen), 3,4,7,8-tetramethyl-1,l0-phenanthroline (tmp), or 2,9-dimethyl-1,l0-phenanthroline (dmp)], C6Cl5HgClL2 (L, = phen, tmp, or dmp), and PhHgClL2 (L2 = phen or tmp), have been prepared, but attempts to prepare PhHgCl bipy or complexes of phenylmercuric bromide were unsuccessful. Evidence that the complexes contain four coordinate mercury has been obtained from infrared spectroscopy. All complexes, except C6Cl5HgCl phen, C6Cl5HgCl dmp, and PhHgCl tmp, undergo complete or partial disproportionation reactions, 2RHgXL2 → L2HgX2 +R2HgL2 (or R2Hg + L2), in boiling benzene. Although disproportionation or low solubility precludes solution studies on the majority of the derivatives, it has been shown that C6F5HgX dmp complexes are monomeric in acetone and that PhHgCl phen undergoes dissociation, PhHgCl phen + PhHgCl + phen, in this solvent. Four-coordinate complexes of mercuric halides with neutral ligands, L,HgX, (L = a neutral unidentate or L, = a neutral bidentate ligand; X = C1, Br, or I), are well kno~n,l-~ but analogous complexes of organomercuric halides, viz. RHgXL,, were unknown prior to this investigation. Reactions of organomercuric halides with ligands generally result in disproportionation, the corresponding diorganomercurial and mercuric halide complex being f~rmed.~-~ In some cases intermediate complexes RHgL+X- have been i~olated~,~ or detected in soluti~n,~-~~ and a 1 : 1 complex of unknown structure between pyridine and cis-2- * Part VI, J. organomet. Chem., in press. Preliminary communications for Part VII: Canty, A. J., Deacon, G. B., and Felder, P. W., Inorg. nzlcl. Chem. Lett., 1967,3,263; Deacon, G. B., and Canty, A. J., Inorg. %ucl. Chem. Lett., 1968, 4, 128. t Chemistry Department, Monash University, Clayton, Vie. 3168. Evans, R. C., Mann, F. G., Peiser, H. S., and Purdie, D., J. chem. Soc., 1940, 1209. Cass, R. C., Coates, G. E., and Hayter, R. G., J. chem. Soc., 1955, 4007. Coates, G. E., and Ridley, D., J. chem. Soc., 1964, 166. Coates, G. E. "Organometallic Compounds." 2nd. Edn, pp. 78-82. (Methuen: London 1960.) Seyferth, D., and Towe, R. H., Inorg. Chem., 1962, 1, 185. Coates, G. E., and Lauder, A., J. chem. Soc., 1965, 1857. Brodersen, K., Chem. Ber., 1957, 90, 2703. Schwarzenbach, G., and Schellenberg, &I., Helv. chim. Acta, 1965, 48, 28. Goggin, P. L., and Woodward, L. A., Trans. Faraday Soc., 1962, 58, 1495. Dessy, R. E., Budde, W. L., and Woodruff, C., J. Am. chem. Soc., 1962, 84, 1172. Aust. J. Chem., 1968, 21, 1757-67