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Bent Metallocenes of Germanium, Tin, and Lead with Aminoboratabenzene Ligands − Crystal Structures of E[3,5‐Me 2 C 5 H 3 BN(SiMe 3 ) 2 ] 2 (E = Ge, Sn, and Pb)
Author(s) -
Zheng Xiaolai,
Herberich Gerhard E.
Publication year - 2001
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200112)2001:12<3013::aid-ejic3013>3.0.co;2-5
Subject(s) - chemistry , tin , crystallography , germanium , trimethylsilyl , ligand (biochemistry) , crystal structure , carbon group , bent molecular geometry , coupling reaction , stereochemistry , medicinal chemistry , organic chemistry , silicon , group (periodic table) , biochemistry , receptor , catalysis
The reaction of GeI 2 , SnCl 2 , or PbCl 2 with two equivalents of lithium aminoboratabenzenes in diethyl ether affords the new sandwich compounds Pb(3,5‐Me 2 C 5 H 3 BNMe 2 ) 2 ( 4 ) and E[3,5‐Me 2 C 5 H 3 BN(SiMe 3 ) 2 ] 2 ( 5: E = Ge, 6: E = Sn, 7: E = Pb). While compound 4 undergoes a redox ligand coupling reaction at ambient temperature to give lead black and ligand dimers, the bis(trimethylsilyl)amino compounds 5 − 7 are thermally stable, and coupling products are only detected under the conditions of mass spectrometry. This difference in stability can be attributed to the different perturbation effects which the B ‐amino groups exert on the electronic properties of the boratabenzene rings. Crystal structure determinations reveal that the compounds 5 − 7 possess a monomeric bent‐sandwich geometry in the solid state with facially bonded boratabenzenes. The E−C distances span rather large ranges [ 5: 2.320−2.939(4) Å; 6: 2.519−3.033(9) Å; 7: 2.632−3.054(7) Å]; the central element E is always particularly close to one of the two α‐C atoms and displays intermediate E−B distances.