Adducts of hexamethylenetetramine with ferrocenecarboxylic acid and ferrocene-1,1 '-dicarboxylic acid: multiple disorder in space groups Fmm2 and Cmcm

Hexamethylenetetramine, C6H12N4, and ferrocenecarboxylic acid, C11H10FeO2, form a 1:2 adduct, (I), which is a salt, viz. hexamethylenetetraminium(2+) bis(ferrocenecarboxylate), (C6H14N4)[Fe(C5H5)(C6H4O2)](2). The dication in (I) is disordered with two orientations at a site of mm2 symmetry in space group Fmm2, while the anion lies across a mirror plane with its unsubstituted cyclopentadienyl ring disordered over two sets of sites. With ferrocene-1,1'-dicarboxylic acid, C12H10FeO4, hexamethylenetetramine forms a 1:1 adduct, (II), in which both components are neutral, viz. hexamethylenetetramine-ferrocene-1,1'-dicarboxylic acid (1/1), [Fe(C6H5O2)(2)].C6H12N4. The amine component in (II) is disordered with two orientations at a site of mm2 symmetry in space group Cmcm, while the acid component is disordered with two orientations at a site of 2/m symmetry. The components in (I) are linked into a finite three-ion aggregate by a single N-H...O hydrogen bond, while the components of (II) are linked into continuous chains by a single O-H...N hydrogen bond.