Bennett, Martin A.Hockless, David C.R.Wenger, Eric2025-03-242025-03-24Scopus:0012430713https://dspace-test.anu.edu.au/handle/1885/733733566Monomeric η1-(3-chloro)-2-pyridyl complexes of nickel(II), NiCl(3-ClC5H3N-2) L2 [L2 = 2PEt3 (1), dcpe (2); dcpe = 1,2-bis(dicyclohexylphosphino)ethane, (C6H11)2 PCH2CH2P(C6H11)2], have been prepared by the reaction of 2,3-dichloropyridine with Ni(COD)2 in the presence of PEt3 or with Ni(η2-C2H4) (dcpe), respectively. Reaction of 2,3-dichloropyridine with NiCl2(PPh3)2 in the presence of zinc gave the dimeric (C,N)-bridged (3-chloro)-2-pyridyl complex [NiCl(μ-3-ClC5H3N-2)(PPh3)]2 (4), which re-forms 1 on addition of PEt3. A similar reaction between NiBr2(PPh3)2 and 3,4-dibromopyridine gave a mixture of the isomers NiBr(3-BrC5H3N-4)(PPh3)2 (5) and NiBr(4-BrC5H3N-3)(PPh3)2 (6), from which the PPh3 ligands could easily be replaced by dcpe to give NiBr(3-BrC5H3N-4)(dcpe) (7) and NiBr(4-BrC5H3N-3)(dcpe) (8). Alkali metal reduction of 2, and of the mixture of 7 and 8, gave unstable species that could not be isolated, which are thought to be nickel(0) complexes of 2,3- and 3,4-pyridyne, respectively, on the basis of their 31P NMR spectra. The structure of 4 has been solved by heavy atom methods and refined by least squares methods.Crystal data, details of data collection, data processing, structure analysis and structure refinement are given in Table 2. The structure of 4 was solved by Patterson methods (PATTY) 33 and was expanded using Fourier techniques (DIRDIF92). 33 All non-hydrogen atoms were refined anisotropically by full matrix least squares. Hydrogen atoms were included at calculated positions (C--H 0.95 ,~) and held fixed. All calculations were performed using the teXsan Structure Analysis Software of the Molecular Structure Corporation. 34 Acknowledgements--We thank the Swiss National Science Foundation for the award of a Fellowship (E.W.) (Grant No. 8220-033162).9English199510.1016/0277-5387(95)00141-Ehttp://www.scopus.com/inward/record.url?scp=0012430713&partnerID=8YFLogxK