The crystal and molecular structure of the coordinatively unsaturated Ni(0) species Ni(PPh₃)₃

Abstract

. Can. J. Chem. 68, 628 (1990). The disproportionation of the complex (Et2N)3Ti(pPCy2)Ni(PPh3) affords the coordinatively unsaturated species Ni(PPh3)3, 1. This compound crystallizes in the triclinic space group P1, with a = 18.483(4) A, b = 16.203(3) A, c = 17.783(4) A, a = 105.85(2)", P = 117.33(3)", y = 92.33(3)", Z = 4, and V = 4464(2) A3. Full-matrix least-squares refinement of 1042 variables using 6484 data ( F: > 3uF: ) gave R = 0.0441 and R , = 0.0438. The two crystallographically independent molecules are essentially identical, each exhibiting a trigonal planar coordination sphere at Ni. The most interesting feature of the structure is the close approach (2.744-3.094 A) of three ortho hydrogens of the PPh3 groups to the Ni centres. The implications of the structural data regarding ortho metallation and the known instability of 1 are discussed. On discute des implications des donnkes de la structure sur la mktallation en ortho et sur l'instabilite bien connue du compose.Mots clis : non-saturk d'un point de vue de la coordination, complexe du nickel avec des phosphines.[Traduit par la revue]

Stoichiometric and Catalytic Reactivity of Ni(6-Mes)(PPh3)2

“…An X-ray crystal structure (Figure ) confirmed the expected trigonal planar geometry, with the sum of the angles at Ni being 360°. The Ni–PPh 3 distances of 2.1477(18) and 2.1607(17) Å are comparable to those in Stephan’s all-phosphine analogue Ni­(PPh 3 ) 3 (2.148(2)–2.156(1) Å), although 1 is devoid of any of the short Ni···ortho–H–C phenyl interactions reported in Ni­(PPh 3 ) 3 . The Ni–C 6‑Mes distance (1.905(6) Å) is noticeably shorter than that in 2 (1.942(2) Å). , …”

“…Deep-red Ni­(6-Mes)­(PPh 3 ) 2 ( 1 , Scheme ) was isolated in the first instance serendipitously following treatment of the Ni­(I) complex Ni­(6-Mes)­(PPh 3 )Br ( 2 ) with an excess of KO t Bu in THF. In contrast to the many well-known examples of zerovalent PdL 3 and PtL 3 complexes with donor L ligands, fully characterized examples for M = Ni are still not that common. ,,, Given that 1 could only be isolated in poor yield (27%) via a presumed disproportionation reaction, a more effective pathway to the product was developed that involved the straightforward addition of a 1:2 ratio of 6-Mes and PPh 3 to a C 6 H 6 solution of Ni­(cod) 2 . This gave 1 in 56% isolated yield.…”

[(dcpp)Ni(η2-Arene)] Precursors: Synthesis, Reactivity, and Catalytic Application to the Suzuki–Miyaura Reaction

“…the disproportionation of the bimetallic complex [(Et 2 N) 3 Ti(μ-PCy 2 )Ni(PPh 3 )], Stephan and co-workers were able to characterize this complex by X-ray analysis. 33 A final example was given in 2013 by Lu and colleagues, using the tridentate ligand N(o-(NHCH 2 PiPr 2 )C 6 H 4 ) 3 . 34 To date, no Xray structures for other [Ni(PR 3 ) 3 ] complexes are known.…”

Tris(tri-o-tolyl phosphite-κP)nickel: a coordinatively unsaturated nickel(0) complex

“…1. Table 2 (Dick et al, 1990) and monovalent [Ni(PPh 3 ) 3 ]BF 4 ÁBF 3 ÁOEt 2 (Saraev et al, 2008), which are the closest analogues available for comparison.…”

“…freedom but less 'bend' than the former ligand. In the case of zero-valent [Ni(PPh 3 ) 3 ], the phenyl rings in each ligand adopt a pseudo-parallel alignment of pairs of phenyl rings on adjacent ligands (Dick et al, 1990). This complex also exhibits ortho-phenyl proton agostic interactions (Cotton & Luck, 1989) with the metal centre.…”