Paramagnetic (1,3‐Diborolyl)ruthenium Triple‐Decker Complexes and Transformation into Diamagnetic Complexes Having Bridging 1,3‐Diborafulvene Ligands

Abstract

The paramagnetic triple‐decker complexes [(Cp*Ru)2{μ‐(CMe)3(BCl)(BMe)}] (3b) and [(Cp*Ru)2{μ‐(CMe)3(BCl)2}] (3c) are formed by refluxing a mixture of [Cp*RuCl]4 and pentamethyl‐2,3‐dihydro‐1,3‐diborole in thf. In CH2Cl2 under air complex 3b slowly looses a hydrogen atom with formation of the diamagnetic triple‐decker [(Cp*Ru)2{μ‐η5:η6‐(CMe)3(BCl)(BCH2)}] (4b) with the unsymmetrical dihydrodiborafulvene derivative in a bridging position. The analogous complex [(Cp*Ru)2{μ‐η5:η6‐(CMe)3(BMe)‐(BCH2)}] (4a) is obtained by interaction of HCl with the triple‐decker [(Cp*Ru)2{μ‐(CMe)3(BMe)2}] (3a). According to calculations, complexes 4a and 4b have an almost non‐distorted triple‐decker arrangement with a strong bending of the B=CH2 group toward one of the Ru atoms. For the formation of 3b and 3c the chloro‐containing sandwich complexes [Cp*Ru{η5‐(CMe)3(BCl)(BR1)}] (2b,c; R1 = Me, Cl) are proposed as intermediates. The constitutions of the complexes are derived from NMR, MS and DFT data, and the molecular structure of 3b is confirmed by an X‐ray diffraction analysis.

Syntheses and Crystal Structures of thecloso-Borates M2[B7H7] and M[B7H8] (M = PPh4, PNP, and N(n-Bu4)): the Missing Crystal Structure in the Series [BnHn]2−(n= 6−12)

“…Until now the crystal structure of [(C 5 H 5 N) 2 CH 2 ][B 7 Br 7 ] is the only example for a closo -heptaborate that was structurally characterized . However, in the sodium boride Na 3 B 20 closo -B 7 and -B 6 units were observed. , Structurally related compounds, which show a pentagonal bipyramid, are, for example, closo -[CB 6 H 7 ] − and its derivatives, , closo -C 2 B 5 H 7 , (1,3-Diborolyl)ruthenium triple-decker complexes and metalladicarboranes . The unknown and missing crystal structure of [B 7 H 7 ] 2− in the series of [B n H n ] 2− ( n = 6−12) of closo -borates was determined.…”

“…47 However, in the sodium boride Na 3 B 20 closo-B 7 and -B 6 units were observed. 48,49 Structurally related compounds, which show a pentagonal bipyramid, are, for example, closo-[CB 6 H 7 ]and its derivatives, 50,51 closo-C 2 B 5 H 7 , 52 (1,3-Diborolyl)ruthenium triple-decker complexes 53 and metalladicarboranes. 54 a Twins in agreement with (-1 0 0, 0 -1 0, 0.41 0 1), percentage of the second component 0.3003 (16).…”

Boron, aluminium, gallium, indium and thallium

“…[161][162][163][164][165] The transformation of paramagnetic (1,3-diborolyl)ruthenium tripledecker complexes into sandwich systems bearing 1,3-diborafulvene ligands has been described by Siebert and co-workers. 166 Boron-chalcogen and pnictogen compounds A combined DFT, AIM (atoms in molecules) and ELF (electron localisation function) study has been carried out on borazine and its heavier analogues containing both pnictogen and chalcogen elements as ring constituents. Compared to the pnictogen substituted rings, chalcogen substituted rings are reportedly found to be less aromatic.…”