Light‐Inducedcis‐transIsomerization of Nitrous Acid Formed by Photolysis of Hydrazoic Acid and Oxygen in Solid Nitrogen

1960 ◽  
Vol 33 (4) ◽  
pp. 1008-1015 ◽  
Author(s):  
John D. Baldeschwieler ◽  
George C. Pimentel
Keyword(s):  
Nitrous Acid ◽  
Hydrazoic Acid ◽  
Solid Nitrogen

Is hydrazoic acid (HN3) an intermediate in the destruction of hydrazine by excess nitrous acid?

1995 ◽  
pp. 3103 ◽  
Author(s):  
Anne M. M. Doherty ◽  
Kevin R. Howes ◽  
Geoffrey Stedman ◽  
Memdoh Q. Naji
Keyword(s):  
Nitrous Acid ◽  
Hydrazoic Acid

THE REACTION OF NITROUS ACID WITH 4-SUBSTITUTED-THIOSEMICARBAZIDES

1957 ◽  
Vol 35 (8) ◽  
pp. 832-842 ◽  
Author(s):  
Eugene Lieber ◽  
C. N. Pillai ◽  
Ralph D. Hites
Keyword(s):  
Nitrous Acid ◽  
Relative Proportion ◽  
Chemical Degradation ◽  
Hydrazoic Acid ◽  
Melting Points ◽  
Pure Nitrogen ◽  
Competitive Reactions ◽  
Azide Ion ◽  
Lower Melting Point ◽  
Aryl Isothiocyanates

The reaction of nitrous acid with 4-alkyl- or 4-aryl-thiosemicarbazides, as well as the reaction of alkyl- or aryl-isothiocyanates with hydrazoic acid, leads to the identical 5-(substituted)amino-1,2,3,4-thiatriazole. This has been established by infrared absorption and chemical degradation studies. The reaction of the 5-(substituted)amino-1,2,3,4-thiatriazoles with aqueous bases leads to two competitive reactions: (1) degradation to an isothiocyanate and azide ion, and (2) isomerization to a 1-substituted-tetrazole-5-thiol, the extent of path (1) or (2) depending on the nature of the substituent. Path (1) predominates when the substituent is alkyl, whereas when the substituent is aryl both paths (1) and (2) occur, the relative proportion depending on the electrical nature of the aromatic group, path (2) increasing as the electronegativity increases. The 1-aryl-tetrazole-5-thiols were found to be thermally unstable at their melting points, degrading more or less violently to one mole proportion of pure nitrogen with the formation of sulphur and organic products of lower melting point as yet unidentified. Theories to account for these observations are presented and discussed.

Hydrogen Bonding of Hydrazoic Acid in Solid Nitrogen

1966 ◽  
Vol 44 (8) ◽  
pp. 3029-3033 ◽  
Author(s):  
George C. Pimentel ◽  
Stuart W. Charles ◽  
Kjell Rosengren
Keyword(s):  
Hydrogen Bonding ◽  
Hydrazoic Acid ◽  
Solid Nitrogen

Organization of tight junctions in the choroid plexus epithelium

1978 ◽  
Vol 36 (2) ◽  
pp. 336-337
Author(s):  
B. Van Deurs ◽  
J. K. Koehler
Keyword(s):  
Choroid Plexus ◽  
Present Report ◽  
Freeze Fracture ◽  
Barrier Properties ◽  
Cell Junctions ◽  
Structural Basis ◽  
Apical Surface ◽  
Choroid Plexus Epithelium ◽  
Solid Nitrogen ◽  
Special Composition

The choroid plexus epithelium constitutes a blood-cerebrospinal fluid (CSF) barrier, and is involved in regulation of the special composition of the CSF. The epithelium is provided with an ouabain-sensitive Na/K-pump located at the apical surface, actively pumping ions into the CSF. The choroid plexus epithelium has been described as “leaky” with a low transepithelial resistance, and a passive transepithelial flux following a paracellular route (intercellular spaces and cell junctions) also takes place. The present report describes the structural basis for these “barrier” properties of the choroid plexus epithelium as revealed by freeze fracture.Choroid plexus from the lateral, third and fourth ventricles of rats were used. The tissue was fixed in glutaraldehyde and stored in 30% glycerol. Freezing was performed either in liquid nitrogen-cooled Freon 22, or directly in a mixture of liquid and solid nitrogen prepared in a special vacuum chamber. The latter method was always used, and considered necessary, when preparations of complementary (double) replicas were made.

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