ELECTRON-DISTRIBUTION IN 1-ORGANO-1H-TETRAZOLE-5-THIOLS - CRYSTAL AND MOLECULAR-STRUCTURE OF 1-METHYL-1H-TETRAZOLE-5-THIOL AND ITS POTASSIUM(18-CROWN-6) SALT

The crystal and molecular structures of both neutral and anionic 1-methyl-1H-tetrazole-5-thiol, as its potassium(18-crown-6) salt, are reported. In the solid state, the molecular thiotetrazole adopts a planar, dimeric arrangement, in which two neighboring molecules are hydrogen bridged. Each monomeric unit exhibits considerable pi electron delocalization over the CN2S fragment. The anionic form displays extensive, but not uniform, pi electron delocalization within the ring, which also extends to the exocyclic carbon-sulfur bond, the structure being best described as a hybrid. The potassium cation is coordinated to the macrocyclic 18-crown-6 ether as expected, but it also interacts with the NCS fragment of the tetrazolethiolate ring.