2633-01-4

Upstream product

• 2530-26-9 3-nitropyridine 
• 462-08-8 pyridin-3-ylamine 

Downstream Products

• 110-86-1 pyridine 
• 460-12-8 Butadiyne 
• 74-90-8 hydrogen cyanide 
• 74-86-2 acetylene 

Relevant academic research and scientific papers

Three isostructural azo-functionalized 3D Cd(II)-coordination polymers for solvent dependent photoluminescence study

Constructions of coordination polymers by applying mixed ligand approach have taken a huge attention to researcher which can be structurally designed by choosing particular components according to the desired applications. An unexploited azo functionalized N,N′ spacer, L = [3,3′-azobis(pyridine)], and three different dicarboxylate co-linkers such as 1,4-naphthalene dicarboxylic acid (NDC), 2-amino terephthalic acid (2-ATA), and 2-nitro terephthalic acid (2-NTA), give rise to three isostructural coordination polymers (CPs) with Cd(II) metal ions with molecular formula of {[Cd(NDC)(L)]·xS}n, (CP-1), {[Cd(2-ATA)(L)]·xS}n (CP-2) and {[Cd(2-NTA)(L)]·xS}n (CP-3) (S = Guest molecules) respectively. All the CPs are constructed via room temperature slow evaporation process and characterized by single crystal X-ray analysis, TGA, FT-IR, PXRD and elemental analysis. The topological analysis reveals that all the CPs feature a 6c-uninodal rare ‘rob’ topology with the point symbol {48·66·8} and possess a dense 3D structure having predefined functionalities on framework backbones. The solvent dependent photoluminescence property has been investigated for all the CPs showing their emissive nature at 379 nm, 419 nm, and 415 nm while excited at 275 nm, 270 nm and 310 nm respectively. The measurements indicates that all the CPs show the quenching in emission spectra for the solvents nitromethane and nitrobenzene.

Two azo-functionalized luminescent 3D Cd(ii) MOFs for highly selective detection of Fe3+ and Al3+

Two cadmium-based 3D luminescent MOFs {[Cd2(SA)2(L)2]·H2O}n (Cd-MOF-1) and [Cd(CDC)(L)]n (Cd-MOF-2) (H2SA = succinic acid, H2CDC = 1,4-cyclohexanedicarboxylic acid, L = [3,3′-azobis(pyridine)]) have been assembled by employing organic dicarboxylic acid linkers with an unexploited azo-functionalized N,N′ spacer via a room temperature slow evaporation process, and they are characterized by single crystal X-ray analysis, TGA, FT-IR, PXRD and elemental analysis. The topological analysis reveals that Cd-MOF-1 features a 6c-uninodal rare 'rob' topology with the point symbol {48·66·8}, whereas Cd-MOF-2 shows a 'pcu' alpha-Po primitive cubic topology with the point symbol {412·63}. These MOFs are highly emissive at 382 nm and 398 nm when excited at 305 nm and 312 nm, respectively. The exposed azo groups are presumed to act as functional sites for the recognition of metal ions through quenching of fluorescence intensity. The fluorescence measurements show that these MOFs can selectively and sensitively detect Fe3+ as well as Al3+ and thus, they demonstrate potential as dual-responsive luminescent probes for metal-ion sensing. EDS elemental mapping, PXRD of loaded MOF materials, and a plausible quenching mechanism have been discussed. More importantly, both the MOFs exhibit rapid response times toward sensing of Fe3+ and Al3+.

Two Closely Related Zn(II)-MOFs for Their Large Difference in CO2 Uptake Capacities and Selective CO2 Sorption

Two azo functionalized Zn(II)-based MOFs, {[Zn(SDB)(3,3′-L)0.5]·xG}n, IITKGP-13A, and {[Zn2(SDB)2(4,4′-L)]·xG}n, IITKGP-13B (IITKGP stands for Indian Institute of Technology Kharagpur), have been constructed through the self-assembly of isomeric N,N′-donor spacers (3,3′-L = 3,3′-azobispyridine and 4,4′-L = 4,4′-azobispyridine) with organic ligand 4,4′-sulfonyldibenzoic acid (SDBH2) and Zn(NO3)2·6H2O (G represents disordered solvent molecules). Single-crystal X-ray diffraction studies reveal the 2D structure with sql topology for both MOFs. However, the subtle change in positions of coordinating N atoms of spacers makes IITKGP-13A noninterpenetrated, while IITKGP-13B bears a 2-fold interpenetrated structure. IITKGP-13A exhibits higher uptake of CO2 over CH4 and N2 with high IAST selectivities for mixed CO2/CH4 (50:50, biogas) and CO2/N2 (15:85, flue gas) gas systems. In contrast, IITKGP-13B takes up very low amount of CO2 gas (0.4 mmol g-1) compared to IITKGP-13A (1.65 mmol g-1) at 295 K. Density functional theory (DFT)-based electronic structure calculations have been performed to explain the origin of the large differences in CO2 uptake capacity between the two MOFs at the atomistic level. The results show that the value of the change in enthalpy (ΔH) at 298 K temperature and 1 bar pressure for the CO2 adsorption is more negative in IITKGP-13A as compared to that in IITKGP-13B, thus indicating that CO2 molecules are more favored to get adsorbed in IITKGP-13A than in IITKGP-13B. The computed values for the Gibbs' free energy change (ΔG) for the CO2 adsorption are positive for both of the MOFs, but a higher value is observed for the IITKGP-13B. The noncovalent types of interactions are the main contribution toward the attractive energies between the host MOF frameworks and guest CO2 molecules, which has been studied with the help of energy decomposition analysis (EDA).

A mild CuBr-NMO oxidative system for the coupling of anilines leading to aromatic azo compounds

An efficient, mild and cost-effective method has been developed utilizing CuBr with N-methylmorpholine N-oxide (NMO/NMMO) for the oxidative coupling of anilines to access symmetrical and unsymmetrical azo compounds in high yield. The reactivity was found to be governed by electronic and steric factors of anilines.

4,4'-Azopyridine as an easily prepared and recyclable oxidant for synthesis of symmetrical disulfides from thiols or alkyl halides(tosylates)/thiourea

Heterocyclic azo compounds, prepared from corresponding amines in one step, are used as effective oxidants for the conversion of thiols into symmetrical disulfides in high yields. Among the studied azo compounds, 4,4'-azopyridine was found to be very efficient for the odorless conversion of alkyl halides into disulfides in the presence of thiourea. An attractive feature of this azo compound is that its obtained solid side product hydrazine is easily separated by filtration and can be recycled to its azo compound for further use.

Pyridyl-and pyridylperoxy radicals-a matrix isolation study

The three isomeric pyridyl radicals 2a-c were synthesised using flash vacuum pyrolysis in combination with matrix isolation and characterised by infrared spectroscopy. The IR spectra are in good agreement with spectra calculated using density functional theory methods. The reaction of the pyridyl radicals 2 with molecular oxygen leads to the formation of the corresponding pyridylperoxy radicals 3a-c. The peroxy radicals 3 are photolabile, and irradiation results in syn-anti isomerisation of 3a and 3b and ring expansion of all three isomers of 3.

Interdependence of structure and physical properties in co-crystals of azopyridines

To establish how intermolecular interactions influence the supramolecular assembly of azopyridines, a total of five co-crystals of 3,3′ and 4,4′-azopyridine; 3,3′-azpy:succinic acid (3,3′-azpy:SA), 3,3′-azpy:adipic acid (3,3′-azpy:AA), 3,3′-azpy:suberic acid (3,3′-azpy:SuA), 3,3′-azpy:sebacic acid (3.3′-azpy:SeA), and 4,4′-azpy:suberic acid (4,4′-azpy:SuA) were synthesized. In all co-crystals of 3,3′-azopyridine, there are infinite 1-D zig-zag tapes composed of alternating 3,3′-azpy and diacids held together by COOH...N(py) hydrogen bonds. Neighbouring chains are arranged into 2-D sheets via secondary inter-chain C-H...O interactions between azopyridine ring hydrogen atoms and carbonyl oxygen atoms in an in-phase manner. However, in the co-crystal of 4,4′-azopyridine:suberic acid, the adjacent chains form 2-D sheets in an out-of-phase motif via two types of inter-chain C-H...O interactions, i.e. between azopyridine ring hydrogen atoms and carbonyl oxygen as well as hydroxyl oxygen atoms. The structural consistency within the 3,3′-azopyridine co-crystals has made it possible to establish a correlation between melting point of the homomeric molecular solids and co-crystals of the corresponding carboxylic acids.

Palladium-catalyzed cascade oxidation/ sp 2 C-H acylation of azoarenes with aryl methanes

A Pd-catalyzed cascade oxidation/sp2 C-H bond acylation of azoarenes was developed in which readily available aryl methanes were used as the in situ generated acyl sources. This reaction provides a convenient access to ortho-acyl azoarenes under mild conditions.

New heteroaromatic azo compounds based on pyridine, isoxazole, and benzothiazole for efficient and highly selective amidation and mono-N-benzylation of amines under Mitsunobu conditions

4,4′-Azopyridine (2c) is used in conjunction with triphenylphosphine for the efficient conversion of carboxylic acids into amides via Mitsunobu reaction with primary and secondary aliphatic and aromatic amines. The highly selective amidation of only primary aromatic amines with new heterogeneous azo compounds based on benzothiazole 2d and isoxazole 2e is also described. These azo compounds 2c-2e can also be applied for selective mono-N-benzylation of primary aromatic amines. The solid side product heteroaromatic hydrazines obtained under the developed Mitsunobu conditions are easily separated by simple filtration and can be reoxidized to azo compounds for further use.

Easily prepared azopyridines as potent and recyclable reagents for facile esterification reactions. An efficient modified mitsunobu reaction

(Chemical Equation Presented) The 2,2′-, 3,3′-, and 4,4′-azopyridines (azpy) and their alkyl pyridinium ionic liquids were studied as a new class of electron-deficient reagents for Mitsunobu esterification reactions. Among these compounds, 4,4′-azopyridine was found to be the most suitable one for esterification and thioesterification reactions. This new reagent promises to provide general and complementary solutions for separation problems in Mitsunobu reactions without restricting the reaction scope and facilitates the isolation of its hydrazine byproduct. The pyridine hydrazine byproduct can be simply recycled to its azopyridine by an oxidation reaction.