Unprecedented Alkene Complex of Zinc(II):  Structures and Bonding of Divinylzinc Complexes

Abstract

This report describes the solid state structures of a series of divinylzinc complexes, one of which represents the only structurally characterized zinc(II) π-complex. Vinylzinc reagents, Zn[C(Me) =CH 2 ] 2 (1) and Zn[C(H)=CMe 2 ] 2 (2), have been synthesized and isolated as white crystalline solids in 66% and 72% yield, respectively. Each compound exhibits an infinite polymeric architecture in the solid state via a series of zinc-π (1) and zinc-σ-bonded (2)

Interaction of Zinc Oxide Clusters with Molecules Related to the Sulfur Vulcanization of Polyolefins (“Rubber”)

“…These distances are in agreement with the corresponding data of the only structurally characterized zinc(II) p complex [Zn-A C H T U N G T R E N N U N G (CMe=CH 2 ) 2 ], for which intermolecular Zn···A C H T U N G T R E N N U N G (C=C) distances of 226-233 pm were determined by X-ray crystallography for the five molecules in the asymmetric unit cell (the p interaction occurs between neighboring molecules). [29] The absolute binding energy of 15 is 11 % larger than with the ethene ligand. An analogous adduct was obtained with 2-methylpent-2-ene (calculated binding energy: À82.9 kJ mol À1 ), which is often used as a model olefin in vulcanization studies.…”

“…[33] Expectedly, the organometallic adduct 15 a is more stable than the isomeric complex 15, by 44.0 kJ mol . [29] Allyl complexes are known to be fluxional, since the hapticity of the ligand can switch back and forth between h 1 and h 3 . [33] Zinc allyl complexes with both bonding types are known [34] but no crystal structures have been reported.…”

Cationic Ethylzinc Compound: A Benzene Complex with Catalytic Activity in Hydroamination and Hydrosilylation Reactions

“…The [ P h H g C B 1 1 F 1 1 ] , 3 1 [ n B u 4 N ] 2 [ C l C u C B 1 1 F 1 1 ] , 3 2 {[(MeCN) 4 Ag 3 ][Ag(CB 11 I 5 Br 6 ) 2 } n , 33 and Ph 3 PAuCB 11 H 11 . 34 Although strong bases such as alkyllithium compounds readily deprotonate carborane anions, 35,36 compounds such as Et 3 Al do not do so.…”

Isomerization of Cyclooctadiene to Cyclooctyne with a Zinc/Zirconium Heterobimetallic Complex

“…[17] Thezirconium and zinc metal centers are bridged by not only the alkyne ligand but also as ingle hydride.T he ZrÀCb ond lengths are consistent with the expected asymmetry of the alkyne bridge and take values of 2.176(1) a nd 2.444(2) f or terminal and bridging carbons,r espectively.T he ZrÀZn distance of 2.7943(3) i sa pproximately 0.1 s horter than that observed in the parent complex Zn·Zr.T he Zn À Cb ond length of 2.198(2) isslightly longer than the 1.9-2.1 range established for terminal ZnÀC s-bonds, [18] but shorter than the range of 2.2-2.3 r eported for strongly p-coordinated alkene complexes of Zn II . [19] Thes hort CÀCb ond length of 1.308(3) a nd obtuse C-C-C bond angles of 129.0(2) and 133.9(2)8 8 support the formulation as ac oordinated cyclooctyne. [20][21][22][23] There is precedent for the structure of 1:t he synthesis of related complexes was pioneered by Buchwald, Erker, and others as part of studies into planar tetracoordinate carbon species of the form R 2 CM 1 M 2 (M 1 = Zr, M 2 = Zr, Al, Ga, B).…”