title: Synthesis, structure, and catalytic applications for ortho- and meta-carboranyl based NBN pincer-Pd complexes.
abstract: o- and m-Carborane-based NBN pincer palladium complexes (oCB-L1)Pd, (oCB-L2)Pd, and (mCB-L1)Pd are synthesized in two steps from commercially available starting materials. The pincer complexes were prepared by the reaction of bis-[R(hydroxy)methyl]-1,2-dicarba-closo-dodecaborane (R = 2-pyridyl oCB-L1, 6-methyl-2-pyridyl oCB-L2) or bis-[2-pyridyl (hydroxy)methyl]-1,2-dicarba-meta-dodecaborane (mCB-L1) with [PdCl2(MeCN)2] under mild conditions. The X-ray structure determination of all carboranyl pincer complexes shows unambiguously B-H activation of the carborane cages. The results agree with the Pd-B bonds in all complexes exhibiting strong σ-electron donation. Theoretical calculations reveal the importance of considering the solid state intermolecular hydrogen bonding when investigating the trans influence in organometallic chemistry. A localized orbitals approach has also been applied to analyze the metal oxidation state in the carboranyl pincer complexes. Catalytic applications of (oCB-L1)Pd and (mCB-L1)Pd have shown the complexes are good catalyst precursors in Suzuki coupling in water and with very low amounts of catalyst loadings.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain.
authors.forename: Min Ying
authors.initials: MY
authors.lastname: Tsang
authors.forename: Clara
authors.initials: C
authors.lastname: Viñas
authors.forename: Francesc
authors.initials: F
authors.lastname: Teixidor
authors.forename: José Giner
authors.initials: JG
authors.lastname: Planas
authors.forename: Nerea
authors.initials: N
authors.lastname: Conde
authors.forename: Raul
authors.initials: R
authors.lastname: SanMartin
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Herrero
authors.forename: Esther
authors.initials: E
authors.lastname: Domínguez
authors.forename: Agustí
authors.initials: A
authors.lastname: Lledós
authors.forename: Pietro
authors.initials: P
authors.lastname: Vidossich
authors.forename: Duane
authors.initials: D
authors.lastname: Choquesillo-Lazarte