Cobalt complexes as the building blocks: {Co3+–Zn2+} heterobimetallic networks and their properties

Abstract

Two {Co(3+)-Zn(2+)} heterobimetallic coordination networks have been synthesized utilizing Co(3+) complex as the building blocks. The structural studies reveal 2D sheet-like networks where the Co(3+) containing building blocks are connected through Zn(2+) ions. Two different building blocks generate two unique networks as evidenced by the crystallographic studies and other properties. These networks are shown to catalyze Lewis metal ion assisted Strecker reaction in heterogeneous manner.

A novel Co3+-based asymmetrical building block: Heterobimetallic metallacycles versus coordination networks

“…The Zn\N pyridine bond lengths are in the range of 2.041-2.065Å while the N pyridine \Zn\N pyridine and Cl\Zn\Cl bond angles were found to be 102.77(15)°to 119.46(8)°, respectively. These bond lengths and angles are comparable to other {Co 3+ -Zn 2+ } complexes of similar structural nature [10,14]. The Zn(II) ion is slightly distorted from an ideal tetrahedral geometry as the τ 4 distortion parameter has the value of 0.92 [23].…”

“…The Co 3+ ion is coordinated by four deprotonated N amide groups in the basal plane whereas two N pyridyl atoms occupy the axial positions. In all three cases, the Co\N amide bond distances are longer than the Co\N pyridine bond distances as observed before [10][11][12]14,15].The crystal structure of 2 [22] reveals that it is composed of a metallacycle, where two building blocks are connected through two Zn(II) ions (Fig. 1).…”

“…Several such building blocks have been used for the preparation of heterobimetallic complexes and networks of highly ordered nature [10][11][12][13][14][15][16]. Notably, our earlier studies have employed symmetrical building blocks to understand the secondary metal mediated self-assembly (Scheme 1).…”

Synthesis, Structures, and Heterogeneous Catalytic Applications of {Co3+–Eu3+} and {Co3+–Tb3+} Heterodimetallic Coordination Polymers

“…These auxiliary functional groups could then be utilized to coordinate a secondary metal ion. This synthetic strategy leads to the generation of heterodimetallic complexes [8][9][10] and networks [11] of a highly ordered nature. Utilizing this strategy, we have recently demonstrated the Co 3+ coordination complex 1 [7] as the building block for the preparation of {Zn 2+ -Co 3+ -Zn 2+ }, [8] {Cd 2+ -Co 3+ -Cd 2+ }, [9] and {Hg 2+ -Co 3+ -Hg 2+ } [9] heterodimetallic complexes (Scheme 1).…”

“…[7][8][9][10][11] A coordination complex as the building block offer many benefits such as spectroscopic and magnetic properties as well as structural rigidity. Such an induced rigidity has the ability to place the auxiliary functional groups in a preorganized conformation with an option to control the geometrical placement of such groups.…”