The reaction of two trisubstituted guanidines N,N‘,N‘ ‘- triisopropylguanidine (TPG) and N,N
‘-diisopropyl-N‘ ‘-2,6-dimethylphenylguanidine (DPArG) with HX or equivalents (X = Cl, Br) yielded the anticipated
guanidinium halide salts. The structures of TPGH+X- (X = Cl, 1), TPGH+X-·H2O (X = Br, 3·H2O), and DPArGH+X-
(X = Cl, 2; Br, 4) were determined by single-crystal X-ray diffraction analysis to examine the potential intermolecular
interactions in these compounds and their influence on the extended structures that were observed. The formation
of strong, charge-assisted hydrogen bonds, NH+···X-, dominates the extended structures. In addition, weaker
interactions between the N-substituents and between the X- anions and CH bonds of the substituents have an
apparent role in the structures of these materials. While the TPGH+ cation displayed a C
3 propeller-type orientation
in the structures of 1 and 3
·H2O, two different isomeric forms for the less symmetric DPArGH+ cations were observed,
and the identity of the anion and of the substituents both appear to be important in determining which form is
obtained. Although the DPArGH+ cation exhibited different isomeric structures in 2 and 4, a common structural
motif consisting of hydrogen-bonded chains was observed in their solid-state structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.