Cocrystals of Naphthalenediols with Aliphatic Amines and Their Photoluminescence Properties

Abstract

The cocrystals of 2,3-dihydroxynaphthalene with 1,4-diazabicyclo[2.2.2]octane (dabco), hexamethylenetetramine (hmta) and piperazine are studied. The cocrystal 2,3-dihydroxynaphthalene with dabco was obtained as hydrate; it has dihydroxynaphthalene-water chains holding the dabco. Similar piperizine cocrystal is obtained as a methanol solvate, it has piperazine -methanol chains holding the dihydroxynaphthalene molecules through hydrogen bonds and it has also NÀH···p interactions. The cocrystals of hexamethylenetetramine (hmta) with positional isomer 2,7-dihydroxynaphthalene is also studied. The self-assembly of cocrystal of 2,7-dihydroxynaphthalene with hmta utilizes only three nitrogen atoms of the hmta out of four nitrogen atoms to have three moderate hydrogen bonds formed between dihydroxynaphthalene and hmta. Each repeat cyclic sub-assembly has one embraced dihydroxynaphthalene molecule and such molecules are associated with OÀH···p interactions. From DFT-calculations on cocrystals of 2,3-dihydroxynaphthalene with the three amines it is observed that the HOMO are localised on amine unit whereas LUMO are localized in the dihydroxynaphthalene ring. The fluorescence emissions of the cocrystals differ in each case depending on the amine used. NÀH···p interactions of piperazine causes complete quenching of fluorescence emission of diol host enabling it to distinguish from the other two amines.[a] Dr.

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

“…Thus, there is necessity of studying the stabilization of dipolar molecules by interacting with other substrates in supramolecular environment. Beside these, the non‐covalent self‐assemblies of multi‐functional compounds are challenging as there are more numbers of hydrogen bond sites and related supramolecular interactions makes different local envionments . Slight variations in crystallization conditions changes conformation, and yield conformational polymorphs .…”

“…Beside these, the non-covalent self-assemblies of multi-functional compounds are challenging as there are more numbers of hydrogen bond sites and related supramolecular interactions makes different local envionments. [9][10][11][12] Slight variations in crystallization conditions changes conformation, [13][14] and yield conformational polymorphs. [15][16][17] For example, while crystallization of pyridinium salt of carboxylic acid subtle changes in the crystallization conditions lead to polymorphs.…”

Stacking among the clips of the poly-aromatic rings of phenazine with hydroxy-aromatics and photophysical properties

“…In the latter case, one will have to leave the favorable hydrogen bonding sites of phenazine free; in fact, such an observation can be possible as the exceptional adducts of poly-hydroxyaromatics violating the Etter's rule have been described with other hosts. 51 The p-stacking among the phenazine rings or dihydroxyaromatics would provide avenues to study the photoluminescence properties in the solid state. This is anticipated, as uorophores such as anthracene p-stacked in different ways operate with different emission mechanisms.…”

Crystal structures of cocrystals of 2,7-dihydroxynaphthalene with isoniazid and piracetam

“…2,7-Dihydroxynaphthalene (DHN) is a compound with O-H groups capable of forming hydrogen bonds and two fused benzene rings capable of forming -interactions. As a result, DHN has been used to obtain cocrystals with -cyclodextrin, phenazine, tetramethylpyrazine, hexamethylenetetramine and the pharmaceutical ingredient progesterone (An ˜ibarro et al, 2001;Brahma et al, 2019;Weyna et al, 2009;Khakhlary et al, 2018;Fris ˇc ˇic ´et al, 2010).…”