90526-45-7Relevant academic research and scientific papers
Halogen Photoelimination from Monomeric Nickel(III) Complexes Enabled by the Secondary Coordination Sphere
Hwang, Seung Jun,Anderson, Bryce L.,Powers, David C.,Maher, Andrew G.,Hadt, Ryan G.,Nocera, Daniel G.
, p. 4766 - 4774 (2015/10/28)
Endothermic halogen elimination reactions, in which molecular halogen photoproducts are generated in the absence of chemical traps, are rare. Inspired by the proclivity of mononuclear Ni(III) complexes to participate in challenging bond-forming reactions in organometallic chemistry, we targeted Ni(III) trihalide complexes as platforms to explore halogen photoelimination. A suite of Ni(III) trihalide complexes supported by bidentate phosphine ligands has been synthesized and characterized. Multinuclear NMR, EPR, and electronic absorption spectroscopies, as well as single-crystal X-ray diffraction, have been utilized to characterize this suite of complexes as distorted square pyramidal, S = 1/2 mononuclear Ni(III) complexes. All complexes participate in clean halogen photoelimination in solution and in the solid state. Evolved halogen has been characterized by mass spectrometry and quantified chemically. Energy storage via halogen elimination was established by solution-phase calorimetry measurements; in all cases, halogen elimination is substantially endothermic. Time-resolved photochemical experiments have revealed a relatively long-lived photointermediate, which we assign to be a Ni(II) complex in which the photoextruded chlorine radical interacts with a ligand-based aryl group. Computational studies suggest that the observed intermediate arises from a dissociative LMCT excited state. The participation of secondary coordination sphere interactions to suppress back-reactions is an attractive design element in the development of energy-storing halogen photoelimination involving first-row transition metal complexes.
Co-ordination Chemistry of Higher Oxidation States. Part 8. Nickel(III) Complexes of Bi- and Multi-dentate Phosphorus and Arsenic Ligands; Crystal and Molecular Structure of .C6H5Me
Gray, Leslie R.,Higgins, Simon J.,Levason, William,Webster, Michael
, p. 459 - 468 (2007/10/02)
The five-co-ordinate nickel(III) complexes have been obtained by Cl2 or NOCl oxidation of in CCl4 or CH2Cl2.The bromides are obtained similarly using Br2-CCl4.On gentle heating, (X = Cl or Br) lose X2 to reform .Unstable X3> have been prepared by halogenation of the dicarbonyl >.The complexes have been characterised by i.r., electronic, and e.s.r. spectroscopy, and by magnetic measurements, and the structure of .C6H5Me established by a single-crystal X-ray study.It is monoclinic, space group P21/n, and has a = 15.567(3), b = 14.627(2), c = 15.151(3) Angstroem, β = 113.38(2) deg, and Z = 4.The structure was refined to R = 0.0562 from 1 583 reflections.The five-co-ordinate nickel is in an approximately square-pyramidal arrangement , and lies above the P2Br2 plane toward the apical bromine.The synthesis and properties of pseudo-octahedral Y are discribed.The compounds mer-X3> have also been obtained, but attempts to prepare nickel(III) complexes with quadridentate phosphines were unsuccessful.
