Abstract: | A variety of Ru(CO)2L(η4enone)] complexes (L = phosphines, phosphites, and arsines, enone = (E)-4-phenylbut-3-en-2-one) have been synthesized. 1H-, 13C-, and 31P-NMR spectra are reported and the X-ray structures of two Ru complexes with L ? Ph3P(7), Et3P ( 10 ) and one Fe complex with L ? Ph3P ( 14 ) are presented. All three compounds crystallize in the same monoclinic space group P21/n with a = 10.575(2) Å, b =9.213(2) Å, and c = 27.608(5) Å, β = 100.04(2)°, Z = 4 for 7 , a = 10.276(3) Å, b = 12.935(3) Å, and c = 14.854(2) Å, β = 96.96(2)°, Z = 4 for 10 , and a = 10.492(2) Å, b = 9.232(3) Å, and c = 27.129(3) Å, β = 98.67(2)°, Z = 4 for 14 . The structures of the Ru complexes are compared with the Fe analogues. In the case of M ? Ru and L ? (EtO)3P, (MeO)3P, and (i-PrO)3P ( 9 , 11 , and 13 , respectively) stereoisomers could be detected by 31P-NMR at room temperature, wich arise from rotation at the coordinated metal centre. |