Chromium and tungsten complexes with a paramagnetic gallaimidazole ligand
- PDF / 944,781 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 72 Downloads / 201 Views
1537
Chromium and tungsten complexes with a paramagnetic gallaimidazole ligand* V. G. Sokolov,а A. A. Skatova,а A. V. Piskunov,а E. V. Baranov,а I. L. Fedushkin,а Y. Zhao,b and X.-J. Yangb aG.
A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, 49 ul. Tropinina, 603137 Nizhny Novgorod, Russian Federation. Fax: +7 (831) 4627 497. Е-mail: [email protected] bCollege of Chemistry and Materials Science, Northwest University, Xi´an, Shaanxi 710127, People's Republic of China. E-mail: [email protected]
The reaction of digallane [(dpp-bian)Ga—Ga(dpp-bian)] (1) (dpp-bian is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene dianion) with chromium or tungsten hexacarbonyl affords the complexes [(dpp-bian)Ga—Cr(CO)5] (2) and [(dpp-bian)Ga—W(CO)5] (3), respectively, containing the neutral radical [(dpp-bian)Ga:]. In both cases, temperature-dependent solvation of the gallium center was observed in a tetrahydrofuran solution. The recrystallization of compound 2 from pyridine gave the new complex [(dpp-bian)(Py)Ga—Cr(CO)5] (4). New compounds 2—4 were characterized by EPR and IR spectroscopy and elemental analysis. The molecular structures of complexes 2—4 were established by single-crystal X-ray diffraction. Key words: gallium, gallaimidazoles, chromium, tungsten, metal—metal bonds, redoxactive ligands, molecular structure.
The first compound containing the anionic gallaimidazole ligand [(dab)Ga:]−{K[(18)-crown-6](thf)2}+ (dab = (But2NCH)2) was described in 1999.1 In subsequent years, the coordination chemistry of the anionic gallaimidazole [(dab)Ga:]− (dab = (2,6-Pri2C6H3NCH)2) was extensively investigated.2 The complexes of [(dab)Ga:]−
with a diversity of Periodic table metals were synthesized,3—12 which confirms the versatility of gallaimidazole as a Ga-donor ligand. Anionic gallaimidazoles are isoelectronic with neutral N-heterocyclic germylenes.13—16 The latter are heavy analogs of Arduengo carbenes, which are currently widely used as ligands in the coordination
Scheme 1
Ar = 2,6-Pri2C6H3
* Dedicated to Academician of the Russian Academy of Sciences A. M. Muzafarov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1537—1543, August, 2020. 1066-5285/20/6908-1537 © 2020 Springer Science+Business Media LLC
1538
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 8, August, 2020
chemistry. Previously, we synthesized complexes of a number of transition metals with the anionic acenaphthenediimine gallaimidazole ligand [(dpp-bian)Ga:]− (dpp-bian is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene): [(dpp-bian)Ga—FeCp(CO)2], [(dpp-bian)Ga—VCp2], [{(dpp-bian)Ga} 2NiCp], [{(dpp-bian)Ga—M(CO) 5}{Na(thf)2}]2 (M = Cr, W), [{(dpp-bian)Ga}2FeCp(CO)][Na(dme)3],17 and [(dpp-bian)Ga—MoCp(CO)3].18 The first neutral carbenoid [(dpp-bian)Ga:] with transition metal, the complex [(dpp-bian)Ga—Mo(CO)5], was prepared by the reaction of digallane [(dpp-bian)Ga—Ga(dpp-bian)]19 (1) with molybdenum carbonyl Mo(CO)6.18 It was also shown that digallane 1
Data Loading...
