211-16-5

Upstream product

• 1711-66-6 benzo[1,2,5]thiadiazole-4,5-diamine 
• 30536-22-2 5-amino-4-nitrobenzo[1,2,5]thiadiazole 
• 16252-88-3 5-nitro-2,1,3-benzothiadiazole 
• 1915-85-1 4-Amino-5-nitrobenzo<1.2.5>thiadiazol 
• 873995-19-8 4-phenylazo-benzo[1,2,5]thiadiazol-5-ylamine 
• 72023-79-1 5-bromo-4-nitro-benzo[1,2,5]thiadiazole 
• 2274-89-7 5-chloro-4-nito-2,1,3-benzothiadiazole 
• 99-56-9 4-Nitrophenylene-1,2-diamine 
• 95-88-5 4-Chlororesorcinol 
• 946-80-5 (benzyloxy)benzene 
• 6583-06-8 4-nitro-1,2,3-benzothiadiazole 

Downstream Products

• 59127-46-7 4-Nitrobenzo<1.2-c:3,4-c'>bis<1.2.5>thiadiazol 
• 59127-47-8 4-Amino-benzo<1,2-c:3,4-c'>bis<1,2,5>thiadiazol 

Relevant academic research and scientific papers

Benzo[1,2-c:3,4-c′]bis[1,2,5]selenadiazole, [1,2,5]selenadiazolo-[3, 4-e]-2,1,3-benzothiadiazole, furazanobenzo-2,1,3-thiadiazole, furazanobenzo-2,1,3-selenadiazole and related heterocyclic systems

The first synthesis of benzo[1,2-c:3,4- c′]bis[1,2,5]selenadiazole has been developed starting from commercially available 4-nitrobenzo-2,1,3- selenadiazole. Improved syntheses of the related heterocycles [1,2,5]selenadiazolo[3,4-e]-2,1,3-benzothiadiazole, furazanobenzo-2,1,3- thiadiazole and furazanobenzo-2,1,3-selenadiazole are also reported.

MEHRFACH THIADIAZOL-UEBERBRUECKTE BENZOL- UND P-BENZOCHINON-RADIKALANIONEN UND IHRE Cr-, Mo- UND W-PENTACARBONYL-KOMPLEXE

Stable radical anions of bis(thiadiazolo)-p-benzoquinone as well as of bis- and tris(thiadiazolo)benzene derivatives form on one-electron reduction using potassium/ cryptand in THF solution.According to the assigned ESR spectra, their electron-rich sulfur centers exhibit especially large spin populations.On addition of THF soluble alkalimetal salts, the ESR signals vanish, whereas with metal hexacarbonyls Me(CO)6 paramagnetic mono- (Me = W) and di(metalpentacrbonyl) (Me = Cr, Mo, W) complexes result, for which HMO-McLachlan calculations suggest preferred coordination at the N centers of the same thiadiazol bridge.

The Crystal Structures of the Benzobisthiadiazole and of the Semihomologous Selenadiazolo-2,1,3-benzothiadiazole

The X-ray structure analyses of the title compounds 1 and 2 were performed. 1: monoclinic, C2/c, a = 9.532(2), b = 11.469(2), c = 7.030(3) Angstroem, β = 110.58(2) deg, Z = 4; 2: monoclinic, P21/a, a = 7.650(2), b = 7.729(2), c = 12.948(3) Angstroem, β = 74.26(2) deg, Z = 4.The structure of 1 was solved by direct methods, that of 2 by Patterson- and successive Fourier-synthesis techniques.The least squares refinement converged for 894 independent reflections with I>2?I to an R-value of 0.032 (Rw = 0.035) in the case of 1 and for 1440 independent reflections to on R-value of 0.045 (Rw = 0.045) in the case of 2.The bond lengths in the thiadiazole rings in 1 and 2 and also in the Se-homologous ring in 2 indicate to a quasi-aromatic ?-system, whereas the aromatic character of the central benzene ring in 1 and 2 is strongly disturbed.The substitution of one S by the homologous Se in 2 induces significant changes of comparable bond lengths in 1 and 2.In the crystal structures of both compounds molecular layers and columnar stacks are formed.Quasi-polimers in form of ribbon like structures are established in 1 by short S***N contacts and in 2 by short Se***N contacts.In 2 (SeN2)x-chains are formed. - Key words: Chalkogen-Diimides, Thia(selena)diazoles, quasi-Aromatic ?-Systems, Columnar Structures, Intermolecular S(Se)***N Contacts