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Design, Synthesis, and Chemistry of Bis(σ)borate and Agostic Complexes of Group 7 Metals
Author(s) -
Saha Koushik,
Ramalakshmi Rongala,
Gomosta Suman,
Pathak Kriti,
Dorcet Vincent,
Roisnel Thierry,
Halet JeanFrançois,
Ghosh Sundargopal
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201701423
Subject(s) - agostic interaction , chemistry , boron , medicinal chemistry , octahedron , amine gas treating , phosphine , crystallography , stereochemistry , crystal structure , metal , catalysis , organic chemistry
A series of new bis(σ)borate and agostic complexes of group 7 metals have been synthesized and structurally characterized from various borate ligands, such as trihydrobis(benzothiazol‐2‐yl)amideborate (Na[(H 3 B)bbza]), trihydro(2‐aminobenzothiazolyl)borate (Na[(H 3 B)abz]), and dihydrobis(2‐mercaptopyridyl)borate (Na[(H 2 B)mp 2 ]) (bbza=bis(benzothiazol‐2‐yl)amine, abz=2‐aminobenzothiazolyl, and mp=2‐mercaptopyridyl). Photolysis of [Mn 2 (CO) 10 ] with Na[(H 3 B)bbza] formed bis(σ)borate complex [Mn(CO) 3 (μ‐H) 2 BHNCSC 6 H 4 (NR)] ( 1 ; R=NCSC 6 H 4 ). Octahedral complex [Re(CO) 2 (N 3 C 2 S 2 C 12 H 8 ) 2 ] ( 2 ) was generated under similar reaction conditions with [Re 2 (CO) 10 ]. Similarly, when [Mn 2 (CO) 10 ] was treated with Na[(H 3 B)abz], bis(σ)borate complex [Mn(CO) 3 (μ‐H) 2 BH(HN 2 CSC 6 H 4 )] ( 3 ) and the agostic complex [Mn(CO) 3 (μ‐H)BH(HN 2 CSC 6 H 4 ) 2 ] ( 4 ) were formed. To probe the potential formation of agostic complexes of the heavier group 7 metals, we carried out the photolysis of [M 2 (CO) 10 ] with Na[(H 2 B)mp 2 ] and found that [M(CO) 3 (μ‐H)BH(C 5 H 4 NS) 2 ] ( 5 : M=Re; 6 : M=Mn) was formed in moderate yield. Complexes 1 and 3 feature a (κ 3 ‐H,H,N) coordination mode, whereas 4 , 5 , and 6 display both (κ 3 ‐H,N,N) and (κ 3 ‐H,S,S) modes of the corresponding ligands. To investigate the lability of the CO ligands of 1 and 3 , we treated the complexes with phosphine ligands that generated novel bis(σ)borate complexes [Mn(μ‐H) 2 (BHNCSC 6 H 4 )(NR)(CO) 2 PL 2 L’] (R=NCSC 6 H 4 ; 7 a : L=L’=Ph; 7 b : L=Ph, L’=Me) and [Mn(μ‐H) 2 BHN(NCSC 6 H 4 )R(CO) 2 PL 2 L’] (R=NCSC 6 H 4 ; 8 a : L=L’=Ph; 8 b : L=Ph, L’=Me). Complexes 7 and 8 are structural isomers with different coordination modes of the bbza ligand. In addition, DFT calculations were performed to shed some light on the bonding and electronic structures of these complexes.