Reaction of Indium Bromide with 1,4-Dilithiotetraphenylbutadiene. Synthesis and Molecular Structure of (Et₂O)₂Li(Br)₂In{(C₄Ph₄)}₂In(Br)₂Li(OEt₂)₂:  A Novel Ten-Membered-Ring Organometallic Complex

Abstract

The present renaissance of organometallic chemistry involving the group 13 metals is due, inter alia, to the stabilization of the M-M (M ) Al, Ga, In) bond. 1 Critical in the development of this chemistry is the judicious choice of organic ligand. The utilization of sterically demanding ligands such as substituted m-terphenyls has proven particularly fruitful in this regard. The general synthetic procedure which affords compounds containing the M-M bond involves reaction of a sterically demanding lithium alkyl or aryl with MCl 3 followed by alkali-metal reduction of the resulting RMCl 2 (R ) alkyl, aryl). Recently, we reported the synthesis and molecular structure of a spirogallane anion, [(Ph 4 C 4 )-Ga(C 4 Ph 4 )] -, isolated from the reaction of gallium trichloride with 1,4-dilithiotetraphenylbutadiene in the presence of 12-crown-4. 2 As an extension of this work, we have investigated the organoindium chemistry of 1,4-dilithiotetraphenylbutadiene and report herein the synthesis 3 and molecular structure 4 of (Et 2 O) 2 Li(Br) 2 In-{(C 4 Ph 4 )} 2 In(Br) 2 Li(OEt 2 ) 2 (I) isolated from the reaction of 1,4-dilithiotetraphenylbutadiene with indium tribromide in diethyl ether (Scheme 1). The title compound, characterized by 1 H and 13 C NMR spectroscopy, elemental analyses, and single-crystal X-ray diffraction, is significant, as it represents the first organometallic compound of indium involving the tetraphenylbutadienylene ligand. Moreover, I is interesting, as it crystallizes as a severely twisted, and quite rare, In 2 C 8 tenmembered ring (Figure 1).(1) (a) Robinson, G. H.

Formation of a diphosphine: synthesis and molecular structure of bis(tetraphenylbutadienyl)diphosphine, (Ph4C4)P–P(C4Ph4)

“…Crucial in the stabilization of (Bu t 3 C 6 H 2 )PNP(C 6 H 2 Bu t 3 ) was the utilization of the sterically demanding 2,4,6-tri-tert-butylphenyl ligand. In a related vein, this laboratory has recently examined the organogroup 13 (III) chemistry of 1,4-dilithiotetraphenylbutadiene resulting in two interesting complexes: (a) a spirogallane anion, 4 5 Herein, we report the synthesis 6 and molecular structure 7 of bis(tetraphenylbutadienyl)diphosphine, (Ph 4 C 4 )P-P(C 4 Ph 4 ) III, readily isolated from reaction of 1,4-dilithiotetraphenylbutadiene, 8 prepared by the action of an excess of metallic lithium on diphenylacetylene, with phosphorus(III) bromide (Scheme 1). This compound, characterized by 1 H, 13 C and 31 P NMR spectroscopy elemental analyses and single-crystal X-ray diffraction (Fig.…”

Organodilithium Intermediates as Useful Dianionic Synthons: Recent Advances

“…Meanwhile, different 1,2-digerma-and 1,2-germasila-3,5-cyclohexadienes 285 were prepared and fully characterized by reaction of the intermediate 283 with appropriate digermaand germasilachlorides (Scheme 60) [124]. A severely twisted In2C8 ten-membered ring system 286 was obtained upon reaction of compound 283 with indium tribromide, the tetraphenylbutadienyl units being bridged by two indium atoms in its structure (Scheme 60) [125]. On the other hand, whereas the reaction of compound 283 with di-, tri-, and tetrachlorosilanes at low temperatures affords the corresponding siloles [126], its reaction with vinyltrichlorosilane at temperatures ranging from -196 to 20ºC yielded the corresponding silacycloheptadiene 287 in good yield, and that represented the first synthesis of a silacycloheptadiene (Scheme 60) [127].…”

Dilithio Spiro Zincacyclopentadienes and Dizinca[10]cycles: Synthesis and Structural Characterization

“…Macro metallacycles are also interesting organometallic structures and have exhibited unique applications . For example, they could be used as special metallization reagents and inverse crown ethers .…”