Preparation and reactivity of rhodium and iridium complexes containing a methylborohydride based unit supported by two 7-azaindolyl heterocycles. Issue 32 (20th July 2018)

• Record Type: Journal Article
• Authors: Da Costa, Rosenildo Correa; Rawe, Benjamin W.; Tsoureas, Nikolaos; Haddow, Mairi F.; Sparkes, Hazel A.; Tizzard, Graham J.; Coles, Simon J.; Owen, Gareth R.
• Is Part Of: Dalton transactions. Volume 47:Issue 32(2018)
• Page Start: 11047
• Page End: 11057
• Publication Date: 2018-07-20
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c8dt02311e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A new methyl substituted scorpionate ligand has been coordinated to group nine complexes. The reactivity of the complexes was explored. Abstract : The synthesis and characterisation of a new anionic flexible scorpionate ligand, methyl(bis-7-azaindolyl)borohydride [ Me Bai ] − is reported herein. The ligand was coordinated to a series of group nine transition metal centres forming the complexes, [Ir( Me Bai )(COD)] (1 ), [Rh( Me Bai )(COD)] (2 ), [Rh( Me Bai )(COD Me )] (2-Me ) and [Rh( Me Bai )(NBD)] (3 ), where COD = 1, 5-cyclooctadiene, COD Me = 3-methyl-1, 5-cyclooctadiene and NBD = 2, 5-norbornadiene. In all cases, the boron based ligand was found to bind to the metal centres via a κ 3 - N, N, H coordination mode. The ligand and complexes were fully characterised by spectroscopic and analytical methods. The structures of the ligand and three of the complexes were confirmed by X-ray crystallography. The potential for migration of the "hydride" or "methyl" units from boron to the metal centre was also explored. During these studies an unusual transformation, involving the oxidation of the rhodium centre, was observed in complex2 . In this case, the η 4 -COD unit transformed into a η 1, η 3 -C8 H12 unit where the ring was bound via one sigma bond and one allyl unit. This is the first time such a transformation has been observed at a rhodium centre.