MOLECULAR-STRUCTURE AND DIMERIZATION OF D-CYCLOSERINE IN THE SOLID-STATE

D-cycloserine (CS) is transformed into cis-3,6-bis(aminooxymethyl)-2,5 -piperazinedione (CS-dimer) in the solid state under a humid atmospher e. This dimerization process was followed by measuring the IR bands ch aracteristic of CS and CS-dimer. The reaction was accelerated by the p resence of increased water vapor. The X-ray analysis of CS monohydrate (CS H2O) revealed that the CS molecules exist as a zwitter ion where the alpha-amino N atom is protonated and the amide N atom is deprotona ted in the crystal. Participation of water molecules was suggested in the dimerization of CS.