title: Synthesis, Chemistry, and Electronic Structures of Group 9 Metallaboranes.
abstract: Dimetallaoctaborane(12) of Ru, Co, and Rh have been well-characterized by a range of spectroscopic techniques and X-ray diffraction studies. Thus, reinvestigation of the Ir-system became of interest. As a result, a slight modification in the reaction conditions enabled us to isolate the missing Ir analogue of octaborane(12), [(Cp*Ir)2B6H10], 1. Compound 1 adapts a geometry similar to that of its parent octaborane(12) and Ru, Co, and Rh analogues. In [M2B6H10+x](M = Ru, x = 2; M = Co and Rh, x = 0), there exist two M-H-B protons. However, a significant difference observed in [(Cp*Ir)2B6H10] is the presence of two Ir-H instead of Ir-H-B protons that eventually controls the reactivity of this molecule. For example, unlike [M2B6H10](M = Co or Rh), the Ir-analogue does not react with metal carbonyl compounds or [Au(PPh3)Cl]. Along with 1, a closo trimetallic 8-vertex iridaborane [(Cp*Ir)3B5H4Cl], 2 was also isolated. Additionally, from another reaction, 12-vertex closo iridaboranes [(Cp*Ir)2B10Hy(OH)z], 3a and 3b (3a: y = 12, z = 0; 3b: y = 8, z = 2), have also been isolated. Further, density functional theory calculations were performed to gain useful insight into the structure and stability of these compounds.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Rosmita
authors.initials: R
authors.lastname: Borthakur
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Sourav
authors.initials: S
authors.lastname: Kar
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Subrat Kumar
authors.initials: SK
authors.lastname: Barik
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Somnath
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Gargi
authors.initials: G
authors.lastname: Kundu
authors.affiliation: Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras , Chennai 60036, India.
authors.forename: Babu
authors.initials: B
authors.lastname: Varghese
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
authors.forename: Sundargopal
authors.identifier: http://orcid.org/0000-0001-6089-8244
authors.initials: S
authors.lastname: Ghosh