Synthesis, Structure, and Topological Studies of Solvates and Salts of a Chiral Zwitterionic Host N-(2-Imidazol-5-yl-1-carboxyethyl)-1,8-naphthalimide

Abstract

A chiral carboxylic acid, (−)-N-(2-imidazol-5-yl-1-carboxyethyl)-1,8-naphthalimide (Hbnap), bearing imide and imidazole functionalities with some structural relevance to tryptophan and histidine amino acids, was designed. Various solvates and salts of Hbnap were synthesized and structurally characterized, namely, Hbnap·H2O (1), 4Hbnap­·MeOH­·3H2O (2), Hbnap·DMSO {DMSO = dimethyl sulfoxide} (3), Hbnap·DMF {DMF = N,N′-dimethylformamide} (4), Hbnap·DMA {DMA = N,N′-dimethylacetamide} (5), Hbnap­·2quinoline (6), Hbnap­·pyridine (7), bnap·Hdbu·2H2O {dbu = 1,8-diazabicyclo­[5.4.0]­undec-7-ene} (8), [H2bnap]­Br­·0.5MeOH (9), [H2bnap]­I­·0.5MeOH (10), [H2bnap]2SO4­·DMF­·H2O (11), and [H2bnap]­NO3 (12). Their packing patterns were analyzed in detail, showing that an interplay of hydrogen bonds, aquation, and π-stacking control the formation of distinct one-, two-, or three-dimensional (1D, 2D, or 3D) supramolecular assemblies. The H-bonded 2D underlying networks of solvates 1–8 were topologically classified revealing three distinct topological types, namely, an undocumented topology in 1 and the 3,4L127 and skl topologies in 2 and 3–8, respectively. In contrast, the [H2bnap]+ salts 9–12 show H-bonded underlying networks that are quite distinct not only in the topology (2C1 in 9 and 10, kgd in 11, and lon in 12) but also in the dimensionality that increases from 1D in halide salts 9 and 10 to 2D in sulfate derivative 11 and 3D in nitrate compound 12. Thermogravimetric analysis studies on the removal of DMSO, DMA, and dbu show that packing by the zwitterionic form of the Hbnap host and the formation of salts impede the elimination of solvent in comparison with conventional hydrogen bonded hosts. UV–vis and fluorescence emission studies were also performed showing that different solvates and salts exhibit strong emission bands with distinct maxima in the 428–487 nm region. A significant enhancement of the fluorescence intensity in comparison with the free Hbnap host molecule occurred in all compounds.

Neutral, Zwitterion, Ionic Forms of 5‐Aminoisophthalic Acid in Cocrystals, Salts and Their Optical Properties

“…The water‐halide interactions are as a consequence of charge‐assisted interactions. Water‐halide bonds are observed in self‐assemblies of various salts . Water molecules participating in the hydrogen bonds with the carboxylic acid as well as with bromide ions water molecules in two independent ways forming robust hydrogen bonded cyclic‐assemblies.…”

Sorption Properties and Nitroaromatic Explosives Sensing Based on Two Isostructural Metal–Organic Frameworks

“…The two layers in one bilayer were stack in AB fashion, where each benzene ring is situated to cover the hexagonal pore of the other layer. If the trinuclear centers and the TTPB 3– ligands were simplified as 6-connected and 3-connected nodes respectively, the simplified network (Figure f) belongs to a (6,3)-connected kgd topology with the Schläfli symbol of (4 3 ) 2 (4 6 ·6 6 ·8 3 ). − The double-layers are packed together in ABC fashion by aromatic π–π stacking (3.827 Å) to form a 3D supermolecular architecture (Figure c–e). The layer-packing framework has 1D open rhombic channels of approximately 6 × 8 Å 2 (measured distance between opposite atoms) along the c -axis (Figure d).…”

“…1f) belongs to a (6,3)-connected kgd topology with the Schläfli symbol of (4 3 ) 2 (4 6 •6 6 •8 3 ). [41][42][43] The double-layers are packed together with ABC fashion by aromatic π-π stacking (3.827 Å) to form a 3D supermolecular architecture ( Fig. 1c-e).…”

Polymorphs, ionic cocrystal and inclusion complex of N-amino-1,8-naphthalimide

“…31 Appropriately functionalized acid or base derivatives form salts or ionic cocrystals [32][33][34][35][36][37] or stabilize zwitterion forms. 38 The stacking effect and the concomitant hydrogen bond donor/acceptor behavior of naphthalimide derivatives make them attractive to generate polymorphs. [39][40][41] On the other hand, the aggregates of naphthalimide derivatives 42,43 and metal complexes 44 provide interesting properties.…”