One of the major reasons for studying chemical kinetics is to use measurements of the macroscopic properties of a system, name: Phthalazine, such as the rate of change in the concentration of reactants or products with time.In a article, mentioned the application of 253-52-1, Name is Phthalazine, molecular formula is C8H6N2
Synthetic and mechanistic studies of the four-electron reduction of dioxygen, N=N, and N=O double bonds by tungsten(II) aryloxide compounds
Reduction of the cyclometalation-resistant aryloxide compounds [W(OC6HPh2-2,6-R2-3,5)2- fCl4] (1, R = Ph; 2, R = Me; 3, R = But) in the presence of a variety of phosphine ligands generates the W(II) species [W(OC6HR2Ph-eta6-C6H4) (OC6HPh2-2,6- R2-3,5)(L)] (4-6) in moderate yield. Compounds 4-6 contain a three-legged piano-stool geometry with one of the aryloxide ligands chelated to the tungsten via an ortho phenyl ring. Solid-state structural parameters for the PMe3, PEt3, and PBun3 adducts 4b-d indicate a shortening of the W-C(ipso) and W-C(para) distances consistent with a tungstanorbornadiene resonance contribution. Solution studies of 4b show that exchange on the NMR time scale of ortho and meta protons occurs at elevated temperatures via phosphine dissociation and not pi-arene dissociation. Reaction of 4b with O2 or the trans-diazines PhN=NPh, TolN=NTol, and PhN=NTol (Tol = 4-methylphenyl) led to the corresponding bis(oxo) and bis(arylimido) derivatives [W(OC6HPh4-2,3,5,6)2(X)2 (PMe3)] (X = O, NPh, Ntol; 7-10, respectively). Structural studies show a trigonal-bipyramidal geometry for 7 and 10 with equatorial O or NAr groups and an axial PMe3. Formation of the mixed-imido species [W(OC6HPh4-2,3,5,6)2(NPh)(NTol)(PMe3 )] (10) did not involve generation of any 8 or 9. Cleavage of nitrosobenzene by 4b led to [W(OC6-HPh4-2,3,5,6)2 (NPh)(O)(OPMe3)] (11) containing terminal oxo and phenylimido groups and a phosphine oxide donor ligand. Compound 4b was also found to ring-open the substrates pyridazine, benzo[c]cinnoline, and phthalazine to produce the three new seven-membered diaza metallacycles 12-14. Structural studies show 12 and 14 to contain planar rings, whereas the two backbone phenyl rings in 13 are twisted by 33 with respect to each other. Structural parameters are more consistent with a formulation as a d0-W(VI) metal center with a 2,7-diazatungstahepta-1,3,5,7-tetraene ring and two tungsten-imido bonds for 12 and 14, although there is some evidence for a 2,7-diazatungstahepta-2,4,6-triene (d2-W(IV) metal center) resonance contribution for 14. A kinetic study of the reaction of 4b with trans-4,4?-dimethylazobenzene (TolN=NTol) to produce 9 was carried out. The rate of disappearance of 4b was monitored using 1H NMR and shown to have a first-order dependence on both [4b] and [TolN=NTol] and inverse first-order dependence on [PMe3]. The kinetic data was fit to a mechanistic model involving fast exchange of azobenzene with PMe3 followed by a rate-determining product formation. The concentration of free PMe3 (strong inhibition) is controlled by the position of the fast coordination equilibrium of the product [W(OC6HPh4-2,3,5,6)2 (NTol)2(PMe3)] (9). Reaction of trans-MesN=NMes (NMes = NC6H3Me3-2,4,6) with 4b was slow even at 100C. However, photolysis to produce cis-MesN=NMes led to rapid room-temperature formation of [W(OC6HPh4-2,3,5,6)2(NMes)2] (15). The many orders of magnitude rate acceleration for cis-diazines over their trans counterparts combined with all the other mechanistic work makes a compelling argument that these cleavage reactions (four-electron reductions) are taking place at a single metal center.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. name: Phthalazine, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 253-52-1, in my other articles.
Reference£º
Phthalazine – Wikipedia,
Phthalazine | C8H6N250 – PubChem