A hypervalent Bismuth(III) derivative of Tetrakis-4-methoxyphenyl porphyrin: Synthesis, spectroscopic characterisation and morphological investigations

Bismuth porphyrin anchored reduced graphene oxide nanocomposites as a fascinating photocatalyst for rhodamine B dye degradation

“…On incorporation of bismuth metal ion into porphyrin core, the bands at 3312/3316cm − 1 disappear due to replacement of two N-H bonds by two N − Bi bonds which is quite informative for successful incorporation of bismuth metal ions into porphyrin core of both the porphyrin rings [53]. On metallation, along with disappearance of N-H related vibrational bands, metal nitrogen bond(N − Bi) related bands also appeared at 1022cm − 1 [27]. In both the porphyrin ligands, the band visible near 1225 cm − 1 corresponds to the stretching vibration of the C-C bond which connects porphyrin ring with para carboxy and para hydroxy aryl groups [32].…”

“…Red shifting of soret as well as Q-Bands and spectral broadening illustrates electronic communication between the bismuth metal ion and porphyrin ligands. Moreover, on incorporation of bismuth ion in porphyrin core of both porphyrins, it is depicted that four lower energy Q-Bands collapses into two bands which is the result of alteration of the D 2 h symmetry of the free base porphyrin to D 4 h symmetry of bismuth complexes [27].The presence of two diagonally positioned hydrogen atoms in its N 4 core are responsible for the D 2 h symmetry of free base porphyrins [44]. The optical absorption spectrum for reduced graphene oxide (RGO)was also recorded in DMF before its anchoring with bismuth porphyrins.…”

“…This electron density difference in the conjugated porphyrins system facilitates intersystem crossing (ISC) of S 1 →T 1 , leading to difference in the emission intensities of P1 and P2. On incorporation of bismuth metal into porphyrin core of both the porphyrins, the photoluminescence emission of both the bismuth porphyrin complexes are somewhat quenched relative to free base porphyrin ligands by reason of internal heavy atom effect leads to distortion of ligands plane [27]. The emission intensity of Bi-P1 and Bi-P2 was also changed upon functionalization of reduced graphene oxide nanosheets.…”

“…Bismuth metal was incorporated into both synthesized metal free porphyrins by using bismuth nitrate salt. Initially, 0.1g of free base porphyrin and 0.8g of bismuth nitrate were re uxed in 40ml of pyridine at 60°C [26][27][28][29]. Progress of the reaction was monitored by UV and 1 H NMRspectroscopy.…”