N-Silatranylmethyl Derivatives of Pyrrole,Indole, and Carbazole

Organosilicon derivatives of pyrrole, indole, carbazole, and 2-methylindole containing (MeO)₃SiCH₂, Et₃SiCH₂, or N(CH₂CH₂O)₃SiCH₂ group on the nitrogen atom were synthesized. Their structure and stereoelectronic parameters were studied by X-ray diffraction, ¹H, ^{1 3}C, ^{1 5}N, and ^{2 9}Si NMR, IR and UV spectroscopy, and dielcometry, as well as by quantum-chemical calculations.     

Crystal and Molecular Structure of Bis(1-Vinylimidazole)diacetatozinc

The crystal and molecular structure of bis(1-vinylimidazole)diacetatozinc (C₁₄H₁₈N₄O₄Zn), a highly effective antidote and antihypoxic drug, was determined [R₁ 0.0335 for 8902 unique reflections with I > 2σ(I) and wR₂ 0.0931 for all 10 752 unique reflections]. The triclinic unit cell contains two independent molecules of the complex, A and B. These molecules have short contacts O?H-C. The zinc atoms in molecules A and B have distorted tetrahedral coordination with the coordination sites occupied by the imidazole nitrogen atoms and acetate oxygen atoms. The lengths of the Zn-N bonds (2.019–2.050 Å) and Zn-O bonds with three acetate groups (1.956–1.958 Å) are typical for zinc complexes, whereas the Zn-O³ bond with one of the acetate groups in molecule A is somewhat longer, 2.009(1) Å; also, there is an additional contact of the zinc atom with the carbonyl oxygen atom of this group (Zn-O⁴ 2.498 Å).