A spiral-like chain from a hydrogen-bonded cyclic dichloride containing a water dimer in a quaternary diammonium dichloride trihydrate

The reaction of benzyl chloride with tetramethylethylenediamine (tmen) results in the formation of the quaternary diammonium dichloride trihydrate (dbtmen)Cl₂·3H₂O 1 (dbtmen is N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium) in good yields. 1 crystallises in the monoclinic P2₁/c space group and its structure consists of N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dication, two chloride anions and three crystal water molecules all of which are located in general positions. The organic dication is H-bonded to the chloride anions and the crystal waters with the help of intra-and intermolecular C-H···Cl and C-H···O interactions, while the chloride anions are linked to the crystal waters via O-H···Cl interactions. One of the crystal waters is linked through an intermolecular O-H···O bond with another water resulting in the formation of a water dimer. The O-H···Cl and O-H···O interactions between the chloride anions and water molecules lead to the formation of a five-membered {O₃Cl₂} cyclic dichloride containing a water dimer. The five-membered rings are linked into a chain with the aid of a O-H···Cl interaction. The organic cations are organised in zigzag fashion on either side of the chain and are further linked to the anionic water chain via weak C-H···O and C-H···Cl interactions, leading to the supramolecular organisation of the rings into a spiral-like of chain. Dedicated to Prof. Sabyasachi Sarkar on the occasion of his 60^th birthday