caa a22 4500 469072199 CHVBK 20180323132924.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF00678415 doi (NATIONALLICENCE)springer-10.1007/BF00678415 Structural and bonding investigation of an unbridged donor-acceptor complex 1-(2,2′-bipyrimidine)-1-(t-butyl)-2, 3-bis(trimethylsilyl) -2,3-dicarba-1-galla-closo-heptaborane(6) [Elektronische Daten] [Narayan Hosmane, Hongming Zhang, Kai Lu, John Maguire, Alan Cowley, Miguel Mardones] The reaction between thecloso-gallacarborane, 1-(t-C4H9)-1-Ga-2,3-(SiMe3)2-2,3-C2B4H4 (1), and 2,2′-bipyrimidine in a molar ratio of 1∶1 in dry benzene produced the unbridged donor-acceptor complex 1-(2,2′-C8H6N4)-1-(t-C4H9)-1-Ga-2,3-(SiMe3)2-2, 3-C2B4H4 (2) as a pale-yellow crystalline solid in 81% yield. The spectroscopic data of2 are almost identical to those of the bridged species 1,1′-(2,2′-C8 H6N4)-[1-(t-C4H9)-1-Ga-2,3-(SiMe3)2-2,3-C2 B4H4]2 (3). However, the single-crystal X-ray structure of2 reveals that the complex consists of only one distorted gallacarborane unit and a bipyrimidine molecule, that acts as a bidentate ligand. The apical gallium in2 is displaced further away from the centroidal position above the carborane than it is in 1. Despite the steric hindrance imposed by the bulky trimethylsilyl groups on the cage carbons, the Ga-C(t-buty) bond is tilted toward the cage carbon atoms. Complex2 crystallizes in the monoclinic space groupP21 witha=11.279 (3),b=10.060 (3),c=11.911 (3) Å,β=94.94 (2)°,V=1346.5 (6) Å3,Z=2,D x=1.24g cm−3, λ(MoKα) F(000)= 528, andT=220 K. Full-matrix least-squares refinement for2 converged at R=0.036 andRw= 0.045 for 3032 observed reflections. Molecular orbital calculations showed that antibonding interactions between the gallium and carborane cage carbons, induced by base complexation, are a contributing factor to the gallium's slip distortion that is found in2. Plenum Publishing Corporation, 1992 Hosmane Narayan Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut Zhang Hongming Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut Lu Kai Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut Maguire John Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut Cowley Alan Department of Chemistry, The University of Texas at Austin, 78712, Austin, Texas, USA aut Mardones Miguel Department of Chemistry, The University of Texas at Austin, 78712, Austin, Texas, USA aut Structural Chemistry Kluwer Academic Publishers 3/3(1992-06-01), 183-190 1040-0400 3:3<183 1992 3 11224 https://doi.org/10.1007/BF00678415 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00678415 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hosmane Narayan Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut NATIONALLICENCE 700 1- Zhang Hongming Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut NATIONALLICENCE 700 1- Lu Kai Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut NATIONALLICENCE 700 1- Maguire John Department of Chemistry, Southern Methodist University, 75275, Dallas, Texas, USA aut NATIONALLICENCE 700 1- Cowley Alan Department of Chemistry, The University of Texas at Austin, 78712, Austin, Texas, USA aut NATIONALLICENCE 700 1- Mardones Miguel Department of Chemistry, The University of Texas at Austin, 78712, Austin, Texas, USA aut NATIONALLICENCE 773 0- Structural Chemistry Kluwer Academic Publishers 3/3(1992-06-01), 183-190 1040-0400 3:3<183 1992 3 11224 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer