Group 11 Metal Chemistry of a Tetradentate Ligand, Phenylene-1,4-diaminotetra(phosphonite), <i>p</i>-C₆H₄[N{P(OC₆H₄OMe-<i>o</i>)₂}₂]₂

The CuI, AgI, and AuI chemistry of a tetradentate ligand (phenylene-1,4-diaminotetra(phosphonite), p-C6H4[N{P(OC6H4OMe-o)2}2]2 (P2NΦNP2) (1)) is described. The flexional conformations in 1 leads to interesting structural variations in transition-metal complexes. The reaction of 1 with 4 equiv of CuX (where X = Br and I) produce the tetranuclear complexes, [{Cu2(μ-X)2(NCCH3)2}2(μ-P2NΦNP2)] (where X = Br (2) or X = I (3)) in quantitative yield. Treatment of 3 with an excess of pyridine, 2-(piperazin-1-yl)pyrimidine, and pyrazole yielded the tetra-substituted derivatives, [{Cu2(μ-I)2(L)2}2(μ-P2NΦNP2)] (where L = pyridine (4), 2-(piperazin-1-yl)pyrimidine (5), or pyrazole (6)). Similar reactions of 3 with 1,10-phenanthroline (phen) and 2,2′-bipyridine in a 1:2 molar ratio afford the disubstituted derivatives, [(Cu2(μ-I))2I2(phen)2(μ-P2NΦNP2)] (7) and [(Cu2(μ-I))2I2(bipy)2(μ-P2NΦNP2)] (8). The o-methoxyphenoxy substituents on phosphorus in complexes 5 and 7 adopt approximately parallel planar conformations and contain lattice solvents. The reaction of 3 with 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio in a dichloromethane−acetonitrile mixture leads to the formation of an ionic complex [N(CH2CH2)3N+CH2Cl]2[(Cu2(Cl)(I)2)2(NCCH3)2(μ-P2NΦNP2)]2− (9), as a result of the chloromethylation of DABCO. Treatment of 1 with 4 equiv of AgClO4 produces [{Ag2(μ-ClO4)2)2(C4H8O)2}2(μ-P2NΦNP2)] (10). Displacement of perchlorate ions in 10 by PhN{P(OC6H4OMe-o)2}2 (PNP) or 2,2′-bipyridine yielded [(μ-PNP)2Ag2(μ-P2NΦNP2)Ag2(μ-PNP)2](ClO4)4 (11) and [{Ag2(bipy)2}2(μ-P2NΦNP2)](ClO4)4 (12), respectively. The similar reaction of 1 with 2 equiv of AgOTf, in the presence of 4,4′-bipyridine, gave a three-dimensional AgI coordination polymer, [{Ag2(C10H8N2)2(CH3CN)2}2(P2NΦNP2)]n(OTf)4n (13). The reactions of 1 with [AuCl(SMe2)], in appropriate ratios, afford the tetranuclear and dinuclear complexes, [(Au2Cl2)2(μ-P2NΦNP2)] (14) and [(AuCl)2(P2NΦNP2)] (15). Complex 14 undergoes moisture-assisted P−N bond cleavage in the presence of PhN{P(OC6H4OMe-o)2}2 to give [p-NH2C6H4N{P(OC6H4OMe-o)2}2Au2Cl2] (17) and [PhN{P(OC6H4OMe-o)2}2Au2Cl2]. The structures of the complexes 5, 7−10, 12−15, and 17 are confirmed by single-crystal X-ray diffraction studies.