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Published November 11, 2004 | public
Journal Article

Structural and spectroscopic studies of three-coordinate copper(I) supported by bis(phosphino)borate ligands

Abstract

The bis(phosphino)borates [(p-^(t)BuPh)_(2)B(CH_(2)PPh_(2))_(2)][ASN] (1[ASN]; ASN = 5-azonia-spiro[4.4]nonane), [Ph_(2)B(CH_(2)P^(i)Pr_(2))_(2)]Li(THF)2 (2[Li]), and [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]^− (3[Li] and 3[Tl]) react with copper(I) reagents to generate anionic and neutral complexes. Reaction of 1[ASN] with CuI provides the 1:1 adduct [[(p-^(t)BuPh)_(2)B(CH_(2)PPh_(2))_(2)]CuI][ASN] (4). CuCl reacts with 3[Li] in THF to afford [[(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]CuCl][Li(THF)_(4)] (5), along with a minor byproduct, the three-coordinate bis(phosphine) adduct {(3,5-Me_(2)Ph)B(CH_(2)P^(t)Bu_(2))_(2)}CuCl (6). An analogous neutral complex, {PhB(CH_(2)P^(t)Bu_(2))_(2)}CuCl (7), can be synthesized directly by reacting CuCl with the neutral phosphino borane PhB(CH_(2)P^(t)Bu_(2))_(2). Reaction of the substituted copper(I) halide Me2S · CuBr with 3[Tl] provides the anionic dimer complex [{[(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]Cu}_(2)(μ-Br)]Tl (8). The neutral solvent adducts [Ph_(2)B(CH_(2)P^(i)Pr_(2))_(2)]Cu(NCCH_(3)) (9) and [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu)_(2))_(2)]Cu(NCCH_(3)) (10) are prepared by the reactions between [Cu(CH_(3)CN)_(4)][PF_(6)] and 2[Li] or 3[Li], respectively. Neutral 10 is a useful precursor to several other neutral species via substitution of the labile acetonitrile ligand, including [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]Cu(PMe_(2)Ph)(11), [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]Cu(Sdouble bond; length as m-dashPMe3) (12), [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)] Cu(2,6-lutidine) (13), and [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]Cu(CN^(t)Bu) (14). Attempts to isolate a neutral monocarbonyl adduct, [(3,5-Me_(2)Ph)_(2)B(CH_(2)P^(t)Bu_(2))_(2)]Cu(CO) (15), are frustrated by the high lability of the CO ligand. The solid-state crystal structures of complexes 6, 8, 9, 10, and 11 have been determined and are described.

Additional Information

© 2004 Elsevier Ltd. Received 1 July 2004; accepted 25 August 2004; Available online 28 October 2004. Financial support from the NSF (CHE-0132216) and the DOE (PECASE) is acknowledged. Larry Henling provided assistance with X-ray crystallography. Christine Thomas generously provided a sample of PhB(CH2PtBu2)2. J.C.T. is grateful to the NSF and to the Moore Foundation for graduate research fellowships. Dedicated to Professor Malcolm H. Green, an inspiring organometallic chemist.

Additional details

Created:
August 22, 2023
Modified:
October 26, 2023