Trans A₂B₂ Porphyrins: Synthesis, Crystal Structure Determinations and Hirshfeld Surface Analysis

Abstract

Trans‐A2B2 porphyrins containing p‐methoxyphenyl (A)/p‐methylphenyl (B) (P4) and p‐chlorophenyl (A)/p‐methylphenyl (B) (P5) at the four meso (−CH=) positions of the tetrapyrrolic macrocycles have been synthesized by employing the two steps modified Adler's methodology. Remarkably, the present synthetic scheme afforded us the needle shaped single crystals of (P4) and (P5) that helped us investigate the three dimensional structural architectures of the prepared Trans‐A2B2 porphyrins. Hirschfeld surface analysis (HSs) was used to visualize the fidelity of the crystal structures of (P4) and (P5). This method permitted the identification of individual types of intermolecular contacts and their impact on crystal packings. Molecules are linked by a combination of H⋅ ⋅ ⋅H and C⋅ ⋅ ⋅H contacts, which have clear signatures in the corresponding fingerprint plots. The effect of incorporating two different non sterically demanding functionalities at the para positions of meso phenyl rings on the optical and thermal properties of symmetric (A4) porphyrins i. e. Tetra‐para‐methoxy phenyl porphyrin P1, Tetra‐para‐methyl phenyl porphyrin P2 and Tetra‐para‐chloro phenyl porphyrin P3, have been investigated and the results have been discussed in detail.

Combinations of meso-(4-carboxyphenyl) and meso-(4- hydroxyphenyl) porphyrins as anti-HIV-1 agents

“…51,52 The observed β-pyrrole splitting patterns (Table-S1) for the synthesized compounds are consistent with AB 3 /AB 3 , cis-A 2 B 2 , trans-ABAB systems as reported in literature. 4,5,47,53,54 As can be seen in the 1 HNMR spectral data (Figures S4, S6-S8, SI), the pyrrolic protons are split into doublet/singlet/doublet, doublet/singlet/singlet/doublet and doublet/doublet corresponding to the differing meso-substitution patterns. The porphyrins consistently show a negative peak at the far right, beyond the signal for TMS; the speci c peak can be attributed to the highly shielded inner NH protons.…”

“…The data conforms to the splitting pattern expected of a cis-A 2 B 2 , trans-A 2 B 2 and AB 3 system. 4,5,47,53,54 The β-pyrrole protons resonate as a multiplet centred at 8.88 ppm for c-PB 2 (OH) 2 , for t-PB 2 (OH) 2 and PB(OH) 3 however, the protons are split into two doublets (centered at 8.81 and 8.91 ppm) and a doublet-singlet-doublet (at 8.79 (J = 2.4 Hz,)-8.82 (s)-9.95 (J = 6.1 Hz) ppm) respectively. The aromatic phenyl protons of the compounds resonated between 7.0 to 8.5 ppm as outlined in Table S3.…”

Synthesis of new <em>meso</em>-porphyrins type A<sub>2</sub> B<sub>2</sub>

“…The porphyrin core has been a fascinating heterocyclic organic macrocycle as an interesting building unit for the design of new supramolecular assemblies and coordination polymers [1]. The extremely remarkable properties of highly conjugated macrocycles have led to their unique roles in diverse fields ranging from photomedicines [2] to dye sensitized solar cells that are well addressed in recent reviews [3][4][5].…”

HIRSHFELD SURFACE ANALYSIS OF CRYSTALS OF COMPLEXES - PRODUCTS OF REACTION IN SYSTEMS МХ2 – 1,10-PHENANTHROLINE – GeO2 – CITRIC ACID (М = Ni, Co; X = Cl, CH3COO)

“…[1]. Одним з найбільш ефективних та часто застосовуваних квантово-хімічних методів, що дозволяє кількісно оцінити поверхні молекул, охарактеризувати водневі зв'язки, p-p стекінг взаємодії в структурах є метод поверхонь Хіршфельда [2][3][4][5][6][7].…”