Silver(i) complexes with a P-N hybrid ligand and oxyanions: synthesis, structures, photocatalysis and photocurrent responses.

Reactions of a P-N hybrid ligand, N,N-bis(diphenylphosphanylmethyl)-3-aminopyridine (3-bdppmapy), with silver oxysalts including AgNO3, AgOAc, AgBz (Bz = benzoate) and AgSal (Sal = salicylate) under different reaction conditions give rise to seven coordination compounds {[Ag4(μ-η,η-NO3)2(μ-η,η(2)-NO3)2](3-bdppmapy)2}n (1), {[Ag4(μ-η,η(2)-NO3)4](3-bdppmapy)2}n (2), {[Ag2(μ-η(2)-OAc)(μ-η,η(2)-OAc)]2(3-bdppmapy)2}n (3), [Ag2(Bz)(μ-η,η(2)-Bz)(H2O)]2(3-bdppmapy)2 (4), {[Ag4(μ-η(2)-Bz)2(μ-η,η(2)-Bz)2](3-bdppmapy)2}n (5), {Ag(Sal)(3-bdppmapy)}n (6) and {[Ag4(Sal)2(μ-η,η(2)-Sal)2](3-bdppmapy)2}n (7). Single crystal X-ray analyses reveal that 1, 5 and 7 have similar 1D chain structures constructed by [Ag4(μ-η(2)-Ox)2(μ-η,η(2)-Ox)2] units (1: Ox(-) = NO3(-); 5: Ox(-) = Bz(-)) or [Ag4(Sal)2(μ-η,η(2)-Sal)2] units (7) and double 3-bdppmapy bridges. Compound 2 has a 2D layer structure derived from [Ag4(μ-η,η(2)-NO3)4] units and single 3-bdppmapy bridges. 3 displays another 2D layer structure formed by [Ag2(μ-η(2)-OAc)(μ-η,η(2)-OAc)] units and double 3-bdppmapy bridges. 4 shows a discrete tetranuclear structure formed by two [Ag2(Bz)(η,η(2),μ-Bz)(H2O)] units and a pair of 3-bdppmapy bridges, while 6 adopts a 1D chain composed by [AgSal] units and single 3-bdppmapy bridges. 6 and 7 as representative samples display high catalytic activity toward the photodegradation of rhodamine B (RhB) in water. Compound 7 shows a better photocatalytic performance than that of 6, which correlates well with the differences in their anodic photocurrent responses and their HOMO-LUMO energy gaps derived from the density function theory (DFT) calculations. The formation of 6 and 7 from AgSal and 3-bdppmapy provides a new approach to the design and assembly of Ag(i)-supported CPs with interesting structural architectures and higher photocatalytic activity.