Reversal of polarization in amidophosphines: neutral- and anionic-κP coordination vs. anionic-κP,N coordination and the formation of nickelaazaphosphiranes

Abstract

Nickel(ii) chloride reacts with the bis(tert-butylamino)diazadiphosphetidine {Bu(t)(H)NP(micro-NBu(t))(2)PN(H)Bu(t)} to form trans-[{Bu(t)(H)NP(micro-NBu(t))(2)PN(H)Bu(t)}(2)NiCl(2)]. In solution and the solid-state each heterocyclic ligand coordinates nickel through one phosphorus atom only. For comparison the solid-state structure of the known trans-[NiCl(2)(PEt(3))(2)] was also determined and it was found that the two complexes have almost identical bond parameters about nickel. The nickel-amidophosphine complexes [{Bu(t)OP(micro-NBu(t))(2)PNBu(t)}NiCl(PBu(n)(3))], [(PBu(n)(3))ClNi{Bu(t)NP(micro-NBu(t))(2)PNBu(t)}NiCl(PBu(n)(3))], and [{Me(2)Si(micro-NBu(t))(2)PNBu(t)}NiCl(PBu(n)(3))] were synthesized and X-ray structurally characterized. In these mono- and di-nuclear nickel complexes the nickel ions are coordinated in pseudo square-planar fashions, by one trialkylphosphine ligand, one chloride ligand and one kappaP,N-coordinated amidophosphine moiety from tert-butylamido-substituted heterocycles. Attempts to create nickel complexes chelated in a kappa(2)P fashion by the o-phenylenediamine-tethered mono- and di-anionic 1-{Me(2)Si(micro-NBu(t))(2)PN} 2-{Me(2)Si(micro-NBu(t))(2)PNH}C(6)H(4) and 1,2-{Me(2)Si(micro-NBu(t))(2)PN}C(6)H(4), respectively, afforded instead [1,2-{Me(2)Si(micro-NBu(t))(2)PN}{Me(2)Si(micro-NBu(t))(2)PN}C(6)H(4)NiCl] and [1,2-{Me(2)Si(micro-NBu(t))(2)PN}{Me(2)Si(micro-NBu(t))(2)PN}C(6)H(4)Ni{PEt(3)}], each complex having kappaP,N and kappaP coordinated amidophosphine ligands.

Synthesis and structural characterisation of group 10 metal(ii) gallyl complexes: analogies with platinum diboration catalysts?

“…The Ga-M bond lengths of the complexes all lie in the known ranges for such interactions 20 and are similar to those in previously reported complexes of 4-, 21 5-3n or 6-membered 22 gallium(I) heterocycles with group 10 metal fragments. It is of interest that the P-M distances in 5, 7 and 8 vary in the series Ni < Pd ∼ Pt as might be expected, whereas in the series, trans-[MCl 2 (PEt 3 ) 2 ], the order is different and unexpected with the palladium compound having a significantly shorter M-P interaction than the other two complexes (M = Ni 2.233 A ˚mean, 23 Pd 2.186 A ˚mean, 24 Pt 2.297 A mean 25 ). The molecular structure of 6 is depicted in Fig.…”

Chemistry of pnictogen(iii)–nitrogen ring systems

“…Some representative examples include the 1 : 1 and 1 : 2 complexes 68 and 69, respectively, 78,79 and the 2 : 1 complex 70 (Chart 19). 80 The cis conformation of cyclodiphosph(III)azanes containing donor functionalities in the substituents on the P(III) centres has been exploited to generate a variety of transitionmetal complexes including metallated macrocycles and coordination polymers. 78,81 The products of the reaction of the cyclodiphosph(III)azanes [ROP(m-t NBu)] 2 [R = C 6 H 4 OMe-2, CH 2 OCH 2 X (X = NMe 2 , SMe, OMe)] with [Rh(CO) 2 Cl] 2 depend on the identity of the hemilabile pendant arms, as well as reaction conditions.…”

“…In contrast to the other metal complexes of the [ t BuNP(m-N t Bu)] 2 22 dianions discussed so far, those involving nickel(II) form strained three-membered rings through coordination to P(III) and N atoms rather than a strain-free N,N9-chelated metallacycle. 80,90 The isolation of threemembered metallacycles is relatively common in nickel(II) chemistry. (84).…”

A mixed-valent cyclodiphosphazane: Transition metal chemistry and cis/trans isomerisation

“…1,2 They find applications in various fields such as coordination chemistry, [3][4][5][6][7][8] in anti-tumour studies 9,10 and in catalytic organic transformations. [11][12][13] The dichlorocyclodiphosphazanes, cis-{ClP(μ-NR)} 2 , have been effectively explored as building blocks in the synthesis of a large range of phosphorus-nitrogen macrocycles.…”