Heterometallic Architectures Based on the Combination of Heteroleptic Copper and Cobalt Complexes with Silver Salts

Abstract

A strategy for the formation of heterometallic coordination polymers based on novel copper(II) and cobalt(III) heteroleptic complexes (acacCN)Cu(dpm) and (acacCN)Co(dpm)(2) (acacCN = 3-cyanoacetylacetonate; dpm = dipyrrin) is presented. Using dipyrrins appended with a p- or m-pyridyl group, dpm-4py and dpm-3py, four novel copper and cobalt complexes were prepared and characterized both in solution and in the solid state. These two classes of complexes show different electrochemical properties upon investigation by cyclic voltammetry in CH(2)Cl(2). While the copper complexes show only irreversible reduction processes, the voltammogram of the cobalt species reveals the presence of two quasi-reversible reductions. In the solid state, the copper(II) compounds self-assemble to form one-dimensional architectures upon coordination of the peripheral pyridyl group to the copper center, as characterized by single-crystal X-ray diffraction. Owing to the filled coordination sphere of the octahedral cobalt centers, the (acacCN)Co(dpm-py)(2) compounds crystallize as isolated molecules. Upon reaction with silver salts, these complexes form crystalline heterometallic architectures with different organization and dimensionality, depending on the nature of the metal center and the position of the nitrogen atom in the pyridyl group. The two copper complexes lead to the formation of trinuclear species, {[(acacCN)Cu(dpm-py)](2)Ag}(+), resulting from coordination of the pyridyl groups to the silver cations. However, while meta-functionalized complexes self-assemble into an extended architecture via weak interaction of the peripheral nitrile of the acacCN ligand to the Ag(+) cation, this interaction is not present in the para-functionalized analogue. In both networks based on the Ag(BF(4)) salt, coordination of the tetrafluoroborate anion to the silver center in the rather rare chelate mode is observed. Upon assembly of the cobalt metallatectons with silver salts, two-dimensional (2D) coordination polymers are obtained in crystalline form, resulting, however, from different sets of interactions. Indeed, no coordination of the peripheral nitrile of the acacCN ligand is observed in the network incorporating the m-pyridyl-appended dpm; coordination of the pyridyl groups to the silver center and d(10)-d(10) interactions lead to a 2D architecture. In the case of the para analogue, a 2D honeycomb network is observed owing to coordination of the Ag(I) ion to two pyridyl nitrogen atoms and to one peripheral nitrile group of a acacCN ligand. This latter polymer represents a geometrical hybrid of the networks reported in the literature based on homoleptic Co(dpm-4py)(3) and Cr(acacCN)(3) complexes.

New aspects in bis and tris(dipyrrinato)metal complexes: bright luminescence, self-assembled nanoarchitectures, and materials applications

“…[80][81][82][83][84][85][86][87] They utilized heterometallic bis(dipyrrinato)metal complex networks using dipyrrin ligands with pyridine or benzonitrile at the meso-position. These peripheral N-bearing moieties may be utilized as additional coordination sites for silver(I) [80][81][82] and cadmium(II) 83,84 centers to form heterometallic coordination polymers. Moreover, silver(I) ions may experience silver(I)-π interactions, which also contribute to network formation.…”

Synthesis and Structure of Iron (II) Complexes of Functionalized 1,5-Diaza-3,7-Diphosphacyclooctanes

“…The Fe-F bond lengths were within the typical range of few known BF 4 -ligated iron (II) complexes (1.96-2.26 Å), which contained only terminally η 1 -coordinated tetrafluoroborate anions [32][33][34][35][36][37][38][39]. The most of known complexes-containing bidentate κ 2 -bound tetrafluoroborate ligands were silver (I) complexes with weakly coordinated BF 4 anions, where the Ag-F distances were relatively long (2.79-3.01 Å) [40][41][42][43]. Only two examples of an almost covalent κ 2 -F 2 BF 2 bonding of tetrafluoroborate anion had been described, namely, the silver (I) complex of cyclodextrine-based diphosphine, where BF 4…”

Functional Supramolecular Architectures of Dipyrrin Complexes

“…A variety of 1D coordination polymers featuring dipyrrin complexes have been found in the crystalline solid state (Halper et al, 2004 ; Kilduff et al, 2010 ; Pogozhev et al, 2010 ; Béziau et al, 2012a , 2014 ; Mazel et al, 2017 ). For example, heteroleptic mono(dipyrrinato)copper(II) complexes with the acetylacetonato-type ancillary ligands were employed as building units (Halper et al, 2004 ; Kilduff et al, 2010 ; Pogozhev et al, 2010 ; Béziau et al, 2012a ). Either the dipyrrin or acetylacetonato-type ligand was connected to an additional coordinating moiety such as the pyridyl and cyano group.…”