Supramolecular assemblies in the crystals of carboxylate salts prepared from a ferrocene β-aminoalcohol

Abstract

(Ferrocenylmethyl)(2-hydroxyethyl)amine ( 1) reacts with mono- (CH 3CO 2H and PhCO 2H) and dicarboxylic acids (HO 2C(CH 2) n CO 2H ( n = 0–2), ( E)- and ( Z)-HO 2CCH CHCO 2H) to give the respective carboxylates, viz [ 1H](RCO 2) ( 2, R = CH 3; 3, R = Ph), [ 1H] 2(O 2C(CH 2) n CO 2) ( 4, n = 0; 5, n = 1; 6, n = 2), [ 1H] 2(( E)-O 2CCH CHCO 2) ( 7) and [ 1H] 2(( Z)-HO 2CCH CHCO 2) ( 8), as defined crystalline solids. Crystal structures of 2– 8 have been determined by single-crystal X-ray diffraction analysis, revealing extensive hydrogen bonding interactions based predominantly on charge-supported N +–H···O − and O–H···O − hydrogen bonds, and on C–H···O contacts. Whereas the crystal assemblies of the monocarboxylate salts propagate preferentially in one dimension ( 2: cross-linked chains, 3: columnar stacks), those of the salts prepared from the dicarboxylic acids (including hydrogenmaleate 8) are best described as layered composite arrays resulting via alternation of polar, hydrogen-bonded layers and of non-polar sheets constituted by the ferrocenyl substituents.