Structural Diversity in Tetrakis(4-pyridyl)porphyrin Supramolecular Building Blocks

Abstract

In memory of a pioneer in crystal engineering, Prof. Israel Goldberg, we report a series of new framework solids, based on the ligand tetrakis(4-pyridyl)porphyrin (TPyP). Spontaneous reactions of TPyP with seven different metal salts under liquid-liquid diffusion at ambient temperature show that the formation of ionic compounds is preferred to coordination polymers due to increased conformational freedom. Two coordination networks, {(HgI2)2(TPyP)}n•4nCHCl3•2nTCE (TCE = 1,1,2,2-tetrachloroethane), and {(Ba(μ1,1-NCS)(μ1,1,3-NCS)(H2O)(MeCN))2(TPyP)}n•4nH2O, displayed a new isomeric form of the known [(HgI2)2(TPyP)]∞ polymeric motif, and a two-2 dimensional honeycomb polymeric motif linked by hydrogen-bonding into a three dimensional moganite (mog) net, respectively. Four protonated porphyrinic salts, [H3TPyP][PF6]3•0.5TCE, [H2TPyP][I3]2•2MeOH, [H4TPyP][UO2Cl4]2•6MeCN, and [H4TPyP][Th(NO3)6][NO3]2, were observed which hydrogen bond to give one-or two-dimensional networks, or in the case of [H4TPyP][UO2Cl4]2•6MeCN, a discrete dinuclear hydrogen-bonded complex. In one case, a neutral, hydrogen-bonded complex, Ce(NO3)3(MeOH)3(H2O)•TPyP•TCE•H2O, was formed which adopts a three-dimensional, self-penetrated variant of the face-centered cubic (fcc) network. These new structures represent hybrid organic-inorganic crystalline compounds in which the multidentate porphyrin units, having both hydrogen bonding, as well as coordination functionalities, are interlinked through the inorganic connectors into self-assembled three-dimensional architectures.This work shows the relative stability of noncovalently bound vs. coordination networks as well as the effective potential of the TPyP building block to construct supramolecular assemblies in the presence or absence of coordinating ions as linkers.

Recent Developments in Porphyrin-Based Metal–Organic Framework Materials for Water Remediation under Visible-Light Irradiation

“…It provides mostly 1D frameworks with the aid of large connecting metal ions such as Hg 2+ . Rogers et al reported one-dimensional (1D) frameworks for the reaction of HgI 2 with free-base H 2 TPyP in mixed solvents [88]. The network structures consist of tetrahedrally coordinated Hg 2+ cations coordinated with free-base H 2 TPyP ligands to form 1D metallomacrocyclic coordination polymers generated beside the crystallographic c-axis (Figure 9).…”

(NH4)2[UO2Cl4]·2H2O, a new uranyl tetrachloride with ammonium charge-balancing cations

“…The other ammonium-based cations include organic-functional groups (Di Sipio et al, 1974a,b;Bois et al, 1976a,b;Gatto et al, 2004;Schnaars & Wilson, 2013;Biswas et al, 2017;Serezkhina et al, 2021). Other types of cations that charge-balance (UO 2 Cl 4 ) 2À in the CSD include pyridinium-based (Graziani et al, 1975;Bombieri et al, 1978;Marsh, 1988;Pospieszna et al, 2008;Deifel & Cahill, 2009;Baker et al, 2010;Andrews & Cahill, 2012;Lhoste et al, 2013;Hashem et al, 2013;Surbella III et al, 2016Carter et al, 2018;Mishra et al, 2019;Pyrch et al, 2020), phenanthroliniumbased (Di Sipio et al, 1981, imidazolium-based (Zalkin et al, 1983;Qu et al, 2014;Kohlgruber, 2022), and phosphoniumbased (Brown et al, 1996;Schnaars & Wilson, 2014) species. Other (UO 2 Cl 4 ) 2À complexes have crystallized in the presence of separate metal complexes (Moody & Ryan, 1979;Rogers et al, 1987Rogers et al, , 1990Pons y Moll et al, 2001;Hashem et al, 2014;Falaise et al, 2015;Zhang et al, 2017;Scho ¨ne et al, 2018), crown ethers (Wang et al, 1986;Rogers et al, 1987Rogers & Benning, 1991;Evans et al, 2002) and porphyrins (Mishra et al, 2019).…”

Ferric Oxide Nanocrystals‐Embedded Co/Fe‐MOF with Self‐Tuned d‐Band Centers for Boosting Urea‐Assisted Overall Water Splitting

“…[25] By contrast, the 3D columnar layered cMOFs or scMOFs with continuous channels demonstrate high electron transport ability. [26] Particularly, the pillared MOFs synthesized using 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) as functional ligand exhibit the adjustable electronic conductivity [27] and structural diversity [28] in light of the features of large planar 𝜋-system, combined electronic properties, chemical reactivity, and structural versatility of TPyP. [29] Consequently, to boost the H 2 production efficiency via the urea-assisted method, it is highly desirable to establish a novel bimetallic pillared scMOFs using TPyP as ligand as the trifunctional electrocatalyst toward the UOR, OER, and HER.…”