thiocyanate isothiocyanic acid 59.09138 imidosulfidocarbon CAS:3129-90-6 58.98297 Isothiozyansaeure HNCS GRHBQAYDJPGGLF-UHFFFAOYSA-N Gmelin:130289 azanediidosulfidocarbon Beilstein:1900391 N=C=S 0 isothiocyanic acid CHNS chebi_ontology CHEBI:24928 [C(NH)S] InChI=1S/CHNS/c2-1-3/h2H Isothiocyansaeure thiocyanic acid hydracid one-carbon compound