Synthesis of a New Potentially Hemilabile Ligand: 1-[2-(Diphenylphosphanyl)ethyl]-3,5-dimethylpyrazole, and Comparison of Its Bonding Properties with the Related 1-[2-(Ethylamino)ethyl]-3,5-dimethylpyrazole Ligand toward RhI

Synthesis and characterisation of new pyrazole–phosphinite ligands and their ruthenium(II) arene complexes

“…Singlets at d = 115.9 and 116.4 ppm, respectively, in the 31 P{ 1 H} NMR spectrum of ligands L 1 and L 2 correspond to diphenylphosphinite groups [9]. The rest of NMR signals are consistent with those reported for related ligands [10,11].…”

“…The most characteristic ligands studied have been: (a) bidentate ligands N(pz)-N(amine) [10,11], N(pz)-O(alcohol, ether) [12][13][14][15], N(pz)-P(phosphine) [10,[16][17][18], and N(pz)-S(thiolate) 0022 [19,20]; (b) tridentate ligands (N(pz)) 2 -N(amine) [21,22], (N(pz)) 2 -O(ether) [23,24], (N(pz)) 2 -S(thioether) [25], (N(pz)) 2 -N(amine)-O(alcohol)groups [26]; (c) tetradentate ligands (N(pz)) 2 -(S(thioether)) 2 [27]. These studies have shown that pyrazole, in general, is the stronger donor group of the ligand, but in the case of ligands containing third period donor atoms (P, S), the pyrazole group can also behave as a labile donor group [20].…”

New cationic palladium (II) and rhodium (I) complexes of [Ph2PCH2C(Ph)N(2,6-Me2C6H3)]

“…Furthermore, there is considerable current interest in hybrid P/N ligands and a search in the Cambridge Structure Database revealed that although a vast number of Groups 9-10 complexes with nitrogen and phosphorus ligands have been characterised structurally, only a relatively small number of Pd(II) cations and Rh(I) cations [54][55][56][57][58][59][60][61][62][63][64][65] containing bidentate N(sp 2 )-P(sp 3 ) donors are reported. Since bulky substituents at the aryl groups of N(sp 2 ) donors have been found to strongly influence the catalytic activity and selectivity of Group 10 complexes [66], it is surprising that no Rh(I) complexes of ligands combining tertiary phosphine donors and (sp 2 )N-aryl donors with bulky ortho substituents have been structurally investigated.…”

Study of the reactivity of tris(pyrazolyl)amine and bis(pyrazolyl)amine ligands toward Rh(I). Crystal structure of [Rh3Cl3(cod)3tdma]·CH3CN (tdma=tris[(3,5-dimethyl-1-pyrazolyl)methyl]amine), a C3-symmetric compound

“…The intramolecular separations RhÁ Á ÁRh are 6.264 (3) A. The Rh-N(3) [35][36][37], Rh-Cl [35,[37][38][39][40], and Rh-C(diolefinics) (cod) [3][4][5]7,41] bond lengths are of the same order as those found in the literature. The Cl-Rh-N3 angle (88.52(11)°) is significantly smaller than those found in the literature for similar compounds [89.…”

“…In our laboratory, a several N1-substituted pyrazolic ligands have been prepared and complexed to metallic atoms. In particular, N-aminoalkylpyrazoles have been coordinated to Rh(I) [3][4][5][6][7].…”