New molecular architectures containing low-valent cluster centres with di- and trimetalated 2-vinylpyrazine ligands: synthesis and molecular structures of Ru5(CO)15(μ5-C4H2N2CH[double bond, length as m-dash]CH)(μ-H)2 and Ru8(CO)24(μ7-C4H2N2CH[double bond, length as m-dash]C)(μ-H)3

Md Monir Hossain; Nahid Akter; Shishir Ghosh; Vladimir N Nesterov; Michael G Richmond; Graeme Hogarth; Shariff E Kabir

doi:10.1039/c9ra03841h

New molecular architectures containing low-valent cluster centres with di- and trimetalated 2-vinylpyrazine ligands: synthesis and molecular structures of Ru₅(CO)₁₅(μ₅-C₄H₂N₂CH[double bond, length as m-dash]CH)(μ-H)₂ and Ru₈(CO)₂₄(μ₇-C₄H₂N₂CH[double bond, length as m-dash]C)(μ-H)₃

RSC Adv. 2019 Jul 4;9(36):21025-21030. doi: 10.1039/c9ra03841h. eCollection 2019 Jul 1.

Authors

Md Monir Hossain¹, Nahid Akter¹, Shishir Ghosh¹, Vladimir N Nesterov², Michael G Richmond², Graeme Hogarth³, Shariff E Kabir¹

Affiliations

¹ Department of Chemistry, Jahangirnagar University Savar Dhaka 1342 Bangladesh sghosh_006@yahoo.com skabir_ju@yahoo.com.
² Department of Chemistry, University of North Texas Denton TX 76209 USA.
³ Department of Chemistry, King's College London, Britannia House 7 Trinity Street London SE1 1DB UK.

Abstract

Reaction of 2-vinylpyrazine with Ru₃(CO)₁₂ results in multiple C-H bond activations to afford penta- and octa-ruthenium clusters, Ru₅(CO)₁₅(μ₅-C₄H₂N₂CH[double bond, length as m-dash]CH)(μ-H)₂ (2) and Ru₈(CO)₂₄(μ₇-C₄H₂N₂CH[double bond, length as m-dash]C)(μ-H)₃ (3), in which a Ru₃ sub-unit is linked to Ru₂ and Ru₅ centres via di- and tri-metalated 2-vinylpyrazine ligands, exhibiting novel coordination modes including the loss of ring aromaticity in 2. The bonding of 2 and the mechanism for the fluxional behaviour of the hydrides have been examined by electronic structure calculations.