Pseudopolymorphism leading and two different supramolecular aggregations in a phosphate monoester: role of a rare water-dimer

Abstract

Whereas 2,6-diisopropyl-and 2,6-dimethylphenyl-phosphate forms a 1-D chain, 2,6-diisopropyl-4-amino-phenylphosphate crystallizes as two different 3-D supramolecular aggregates.The first pseudopolymorph 1a is a porous framework built around a rare water-dimer template that undergoes single-crystal to single-crystal transformations to yield desolvated form 1b. The second-pseudopolymorph 1c, obtained by re-crystallisation of 1a in methanol, is a dense 3-D framework.

Synthetic strategies to achieve further-functionalised monoaryl phosphate primary building units: crystal structures and solid-state aggregation behavior

“…Secondly, the presence of halides along with P-OH group within the same molecule can lead to interesting O-HÁ Á ÁX hydrogen bonding interactions resulting in supramolecular aggregation of phosphate molecules in the solid state similar to those reported by us for the different polymorphs of 4-amino-2,6-diisopropyl phenyl phosphate. 10 Monoaryl phosphates 1-3 have been synthesized via phosphorylation of the corresponding 4-halo-2,6-diisopropyl phenol with POCl 3 in the presence of a catalytic amount of anhydrous LiCl followed by hydrolysis of a dichloridate compound with a stoichiometric amount of water dissolved in acetone (Scheme 2). The isolated phosphates 1-3 have been found to be analytically pure and further characterized by a variety of spectroscopic techniques.…”

“…Nucleophilic substitution of 2,6-dialkylphenol can take place only at the 4-position, which was recently exploited by us to prepare 4-amino-2,6-diisopropyl phenyl phosphate (through the nitration route shown in Scheme 1). 10 This compound exhibits pseudo-polymorphism apart from displaying interesting H-bonded supramolecular one-dimensional porous structures that undergo SC-SC transformation. In a similar vein, in the present study, the halogenation pathway of 2,6-dialkylphenol has been investigated to prepare a series of 4-halo-substituted 2,6-diisopropyl phenols.…”

2,6-(Diphenylmethyl)-Aryl-Substituted Neutral and Anionic Phosphates: Approaches to H-Bonded Dimeric Molecular Structures

“…The slight lengthening of this P=O bond in 9 CH3COCH3 is the result of the hydrogen‐bonding which involves this bond ( vide infra ). Other phosphate monoesters where the P=O unit is involved in hydrogen‐bonding also exhibit a similar increase of the P=O bond length: 2,6‐ i Pr 2 C 6 H 3 P(O)(OH) 2 (1.4917(18) Å), 2,6,– i Pr 2 ‐4‐X–C 6 H 2 P(O)(OH) 2 (X=Cl: 1.474(3) Å, X=Br: 1.4926(17) Å, X=I: 1.500(5) Å) ,…”

Solvent-assisted monomeric molecular structure of the phosphate diester and the synthesis of menthol-based phosphate diesters

“…[1][2][3][4][5][6][7][8][9] Such compounds are present as H-bonded structures either through intermolecular association or through interaction with solvent molecules through the donor (P-OH) and acceptor (P=O) moieties. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] These hydrogen bonding interactions in phosphates lead to the formation of various types of aggregates in the solid-state. [26][27][28] Structures of these aggregates depend on the solvent of crystallization and the steric bulk of the substituents.…”