Structural, Vibrational, Thermal, and Electrochemical Studies of a Cyclohexaphosphate Complex, (C₅H₁₄N₂)₂Cd₂CL₂P₆O₁₈.4H₂O

Homopiperazine (Hexahydro-1,4-diazepine)

“…The bond lengths and angles in the symmetrical molecule are unremarkable, with the exception of the carbon-carbon bond of the N-CH 2 -CH 2 -N moiety, which is rather long at 1.603(10) Å. This may be compared with a mean value of 1.524 Å for sp 3 CH 2 -CH 2 in general [29] and is in stark contrast to the values of 1.5204(15) and 1.5190 (15) Å observed in piperazine hydrate [30], the value of 1.513(2) Å in the monoprotonated homopiperazinium perchlorate [31] and 1.521(4) Å in an N,N'-dibenzylatedhomopiperazine [32]. The reason for the long bond in this case is unclear, although other examples of such long NCH 2 -CH 2 N bonds have been located [33].…”

“…At present, it is commercially available from several major suppliers and it has recently found various applications, including as a component of liquids for CO 2 capture [4] and as a component of various organic and organic/inorganic supramolecular ionic salts and transition metal complexes. In these latter applications, the materials are often characterised by X-ray diffraction and so there are a large number of X-ray structures involving a homopiperazinium dication in salts or mixed salts with, for example, carboxylic acids [5][6][7], potassium perchlorate [8], ammonium perchlorate [9], manganese sulfate oxalate [10], cobalt sulfate [11], zinc phosphate [12], arsenic oxide [13], tellurium phosphate [14], cadmium phosphate [15], cadmium chlorides [16,17], lead bromide [18], bismuth iodide [19], uranium fluoride [20] and uranium sulfate [21]. There are also a significant number of structures in which homopiperazine acts as a bidentate ligand on nickel [22,23], copper [24] and platinum [25][26][27][28].…”