Electronic structural studies of newly synthesized sterically hindered analogues of -benziporphodimethene and its metal complexes

• Published in: New journal of chemistry Vol. 47; no. 47; pp. 21897 - 2194
• Main Authors: Kumar, Sachin, Ahluwalia, Deepali, Kubba, Ritika, Bag, Arijit, Warkar, Sudhir Gopalrao, Kumar, Anil
• Format: Journal Article
• Published: 04.12.2023
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj00954h

The presence of syn and anti -conformers in tetramethyl substituted meta -benziporphodimethenes has been well studied. Herein, we report a new sterically hindered hexaaryl- m -benziporphodimethene ( m -BPDM) using benzaldehyde and its Zn( ii ) and Cd( ii ) complexes. The UV-Vis, mass, and NMR characterized data confirmed the synthesis of these m -BPDM analogues. Time-dependent DFT analysis has been performed to visualize the distribution of electron density at the HUMO and LUMO. The present work primarily focuses on the comparative study of the syn , anti -conformers of metallated meta -benziporphodimethenes upon increasing the bulkiness at the sp 3 meso carbon atoms. The placement of -H, -CH 3 , and -Ph groups at the C6- and C21-positions of m -BPDM greatly impacts the stability of these conformers, which has been explored. Along with this, a comparison has also been drawn between the reported X-ray crystallographic geometry and B3LYP/LANL2DZ optimized structures for free-base tetramethyl- m -BPDM and its Zn( ii ) and Cd( ii ) complexes. The article sums up the much-anticipated results from the tetramethylene analogue of m -BPDM, which were contrary to that of tetraphenylene analogues. meta -BPDM is a new type of discrete conjugated porphyrinoid system and shows tremendous properties related to fluorescence and different behaviors with substituents on the sp 3 meso carbons.