Reaction of chloroacetylenephosphonates with 5-thiotetrazoles

1-Chloroacetylene-2-phosphonates react with 1-substituted 5-thio-1H-1,2,3,4-tetrazoles in anhydrous acetonitrile to form new fused heterocycles, 6-(dialkoxyphosphoryl)-3H-[1,3]thiazolo[3,2-d][1,2,3,4]tetrazol-7-ium chlorides, with a small quantity of Z-dialkyl (1,2-bis{[1-amino(methyl/phenyl)-1H-tetrazol-5-yl]sulfanyl}ethenyl)phosphonates.     

Synthesis and Characterization of Niobium-Bearing Members of the NZP and NbOPO 4 Structural Families

Theoretically predicted by us, M 1/3 Nb 5/3 (PO 4 ) 3 (M = Mg, Mn, Co, Ni, Cu or Zn) compounds with the sodium zirconium phosphate (NZP) framework structure having no interstitial ions were synthesized. The rising of temperature above 900;C causes the change of chemical composition of NZP compounds and formation NbOPO 4 -like products. The phase formation regularities stated gave a possibility to choose optimal conditions for preparation of these phosphates.     

Consecutive expansions of -out-of- systems

We introduce consecutive expansions of k–out–of–n systems, which have the property that components are totally ordered by the node criticality relation and with respect to well-known structural importance measures. We propose some formulae to easily compute these measures and study the hierarchies induced for them for large systems.