Structure, Thermal Behavior and IR Investigation of a New Organic Cyclohexaphosphate

Abstract

Physicochemical properties of the bis[1-(2-ammoniumethyl) piperazinium] cyclohexaphosphate hexahydrate are discussed on the basis of X-ray crystal structure investigation. [C6H18N3]2P6O18·6H2O is triclinic,P1, witha= 9.714(2) Å,b= 10.538(2) Å,c= 8.095 Å, α = 87.88(2)°, β = 93.48(2)°, γ = 83.20(1)°, and Z = 1. The structure has been solved using direct methods and refined to a reliabilityRfactor of 0.0307 for 2291 reflections. The compound is characterized by infinite layers of inorganic polyanions approximately parallel to the (001) planes. Organic cations are sandwiched between these layers. OW–H···O and N–H···O hydrogen bonds link P6O18groups, respectively, in a layer and in successive layers as to build a framework in a three-dimensional way. Two water molecules leave this compound at room temperature giving a stable tetrahydrate phase. The structure reorganization is discussed on the basis of OW H-bonds by TG-DTA and DSC thermal analyses. The reported IR study is supported by a detailed theoretical group analysis applied to P6O18withD6hideal local symmetry.