Synthesis and study of new binuclear compounds containing bridging (μ-CN)B(C₆F₅)₃and (μ-NC)B(C₆F₅)₃systems

Abstract

The new compounds [K(18-crown-6)][SCNB(C 6 F 5 ) 3 ] (1), [K(18-crown-6) 7b). In the compounds 3, 4, 6 and 7a the anion [NCB(C 6 F 5 ) 3 ] Ϫ is coordinated to the metal through the nitrogen. Complexes 1, 2 and 7b incorporate a (µ-CN)B unit. The compounds containing the isomeric bridging (µ-CN)B or (µ-NC)B systems have been investigated by 11 B{ 1 H} NMR spectroscopy and by DFT calculations. The 11 B{ 1 H} NMR spectra enable distinction between the isomers. The single-crystal X-ray structures of 1, 3 and 7a have been determined.

Strongly Phosphorescent Neutral Rhenium(I) Isocyanoborato Complexes: Synthesis, Characterization, and Photophysical, Electrochemical, and Computational Studies

“…, which are in the typical range of the isocyanoborato complexes [8][9][10] and lower than that observed in MeCNB(C 6 F 5 ) 3 (2367 cm À1 ) [12] owing to the p-back-bonding interaction.…”

“…[14] The CN and NÀB distances are in the range of 1.14-1.19 and 1.54-1.59 , respectively, which are in the typical ranges (CN: 1.132-1.174 , NÀB: 1.548-1.618 ) reported in other isocyanoborato transition-metal complexes. [8][9][10] UV/Vis absorption and emission properties…”

“…Complexes {Re(CO) 3 (N^N) [CNB(C 6 F 5 ) 3 ]} (1 a-6 a, N^N= diimine ligand) and [Re(CO) 3 (phen)(CNBCl 3 )] (3 c) were prepared in moderate yields from the Lewis acid-base reactions between the cyano precursor complexes with B(C 6 F 5 ) 3 and BCl 3 , respectively, in dichloro-methane. [8,9] When the stable tetraphenyl borate salt and its substituted phenyl derivatives such as NaBPh 4 , KB(C 6 H 4 Cl) 4 and NaB [C 6 H 3 (CF 3 ) 2 ] 4 are available, the corresponding isocyanoborato complexes can be obtained by the reactions of the cyano precursor complexes with the respective borate salts in acidified methanolic solution. [10] These reactions are illustrated in the preparation of [Re(CO) 3 (N^N)(CNBPh 3 )] (1 b-4 b) and [Re(CO) 3 (phen)(CNBR 3 )] [3 d: R= C 6 H 4 Cl; 3 e: R= C 6 H 3 (CF 3 ) 2 ].…”

“…[8,9] The resulting solution was refluxed overnight, during which the solution changed from yellow to pale yellow. After removing the solvent under reduced pressure, the residue was purified by column chromatography on silica gel with dichloromethane as eluent.…”

Structural investigations on new iron-acyl derivatives of B(C6F5)3

“…The latter resonances are shifted up-field with respect to B(C 6 F 5 ) 3 by ca. 50 ppm [19,[21][22][23]]. Table 2 contains selected molecular parameters.…”