The Influence of Solvent on the Crystal Packing of Ethacridinium Phthalate Solvates

Abstract

The synthesis, structural characterization and influence of solvents on the crystal packing of solvated complexes of ethacridine with phthalic acid: 6,9-diamino-2-ethoxyacridinium phthalate methanol solvate (1), 6,9-diamino-2-ethoxyacridinium phthalate ethanol solvate (2), 6,9-diamino-2-ethoxyacridinium phthalate isobutanol solvate (3), and 6,9-diamino-2-ethoxyacridinium phthalate tert-butanol solvate monohydrate (4) are described in this article. Single-crystal XRD measurements revealed that the compounds 1–4 crystallized in the triclinic P-1 space group, and the 6,9-diamino-2-ethoxyacridinium cations, phthalic acid anions and solvent molecules interact via strong N–H···O, O–H···O, C–H···O hydrogen bonds, and C–H···π and π–π interactions to form different types of basic structural motifs, such as: heterotetramer bis[···cation···anion···] in compound 1 and 2, heterohexamer bis[···cation···alcohol···anion···] in compound 3, and heterohexamer bis[···cation···water···anion···] in compound 4. Presence of solvents molecule(s) in the crystals causes different supramolecular synthons to be obtained and thus has an influence on the crystal packing of the compounds analyzed.

Structural Characterization of Multicomponent Crystals Formed from Diclofenac and Acridines

“…The similar heterohexamer we observed in the crystal structures of ethacridinium phthalate isobutanol solvate [66], where instead of the ethanol molecule there is an isobutanol molecule, but the distance between mean planes of ethacridinium is longer in the crystal of compound 2 (3.431 Å and 3.545 Å in the crystal of ethacridinium phthalate isobutanol solvate and compound 2, respectively). In the crystal structure of compound 2, neighboring heterohexamers are linked via π-π interactions and π-stacked columns of ethacridine are formed, whereas inversely oriented diclofenac anions interact through π-π interactions each other and linked these columns.…”

“…This is due to fact that acridines can intercalate into DNA which makes them exhibit anticancer, antibacterial, antiprion, and antiviral effects, among others [58][59][60][61][62]. Our previous research shows that acridine and its derivatives may interact with coformer molecules through various intermolecular interactions, such as hydrogen bonds, halogen bonds, π-π stacking interactions, and are able to form good quality crystals that are stable at room temperature [63][64][65][66]. One of the acridine derivatives represent interesting medicinal activity is ethacridine.…”

Crystal Structure, Hirshfeld Surface Analysis and Energy Framework Calculations of Different Metal Complexes of a Biphenol-based Ligand: Role of Solvent and Transition Metal Ion

“…The employment of different crystallization solvents can produce indeed different crystal forms, where the solvent molecules could affect the solid state assembly [4,5]. The effect of the solvent can indeed influence the growth, the morphology and the packing of crystal structures [6][7][8][9][10][11][12][13][14], so that the same ligand can crystallize in different forms [4].…”

Exploring the molecular landscape of multicomponent crystals formed by naproxen drug and acridines

“…28,29 Recently we have presented results regarding the capabilities of different solvents to induce cocrystallization in acridine-based molecular crystals of APIs. 30 Some of us demonstrated that, in similar cases, cocrystallization 31 and solid-state reactions 32 can be carried out directly in the solid state under dry conditions with high conversion rates and with the additional advantage of eliminating solvents. 33 In this work, the cocrystallization of naproxen with some acridines is thus attempted by three different approaches: (i) solution methods, (ii) liquid-assisted grinding (LAG), and (iii) solidstate thermal approach, heating the sample just below or above the melting point of the reactants to explore the molecular landscape of the target compounds.…”