Work

Kinetic trapping of a cobalt( ii ) metallocage using a carbazole-containing expanded carbaporphyrinoid ligand

Year: 2021

Type: article

Abstract: -unsubstituted expanded porphyrinoid 3, incorporating two carbazole moieties, acts as an effective ligand for Co(ii) and permits the isolation and X-ray diffraction-based characterization of a 6 : 3 metal-to-ligand metallocage complex that converts spontaneously to the constituent 2 : 1 metal-to-ligand metalloring species in chloroform solution. The discrete metalloring is formed directly when the Co(ii) complex is crystallized from supersaturated solutions, whereas crystallization from more dilute solutions favors the metallocage. Studies with two other test cations, Pd(ii) and Zn(ii), revealed exclusive formation of the monomeric metalloring complexes with no evidence of higher order species being formed. Structural, electrochemical and UV-vis-NIR absorption spectral studies provide support for the conclusion that the Pd(ii) complex is less distorted and more effectively conjugated than its Co(ii) and Zn(ii) congeners, an inference further supported by TD-DFT calculations. The findings reported here underscore how expanded porphyrins can support coordination modes, including bimetallic complexes and self-assembled cage structures, that are not necessarily easy to access using more traditional ligand systems.

Source: Chemical Science

DOI: 10.1039/d1sc06514a

Authors: Weinan Zhou, Tridib Sarma, Yonghuan Su, Chuanhu Lei, Jonathan L. Sessler

Institutions: Shanghai University, Cotton University, The University of Texas at Austin

Language: English

Topic: Porphyrin and Phthalocyanine Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: diamond