Papo, Tshephiso R. published the artcileTuning the ¦Ð-backbonding and ¦Ò-trans effect of N?N? coordinated Pt(II) complexes. Kinetic and computational study, Recommanded Product: 1,1-Dimethylthiourea, the publication is Journal of Coordination Chemistry (2015), 68(5), 794-807, database is CAplus.
The nucleophilic substitution reaction of cyclometalated substituted 2,6-dipyridylphenyl platinum complexes [PtLnCl] (n = 1-4; HL1 = 1,3-di-2-pyridylbenzene; HL2 = 1-fluoro-3,5-di-2-pyridylbenzene; HL3 = 1-fluoro-2,4-di-2-pyridylbenzene; HL4 = 1-methyl-3,5-di-2-pyridylbenzene) with thioureas R1R1NCSNR2R2 (TU, R1 = R2 = H; DMTU, R1 = Me, R2 = H; TMTU, R1 = R2 = Me) as a series of neutral nucleophiles with different steric properties, was studied under pseudo-first-order conditions in methanol solution of an ionic strength of 0.1 M (0.09 M LiOTf and 0.01 M LiCl). The rate of substitution of the chloro ligand was studied as a function of nucleophile concentration and temperature using UV-visible and stopped-flow spectrophotometric techniques. The observed pseudo-first-order rate constants for the substitution reactions obey the rate law kobs = k2[Nu] + k-2. The reactivity of the investigated complexes when [PtL1Cl] is used as a reference follows the order [PtL2Cl] > [PtL3Cl] > [PtL4Cl] > [PtL1Cl]. The lability of the chloro group is dependent on the extent of ¦Ð-backbonding and the ¦Ò-trans effect of the ligand backbone. [PtL2Cl] and [PtL3Cl], which have a common electron-withdrawing fluoride on the ligand trans to the leaving group, have a higher reaction rate compared to [PtL4Cl], which has an electron-donating Me group attached to the ligand backbone. The position of the substituent on the Ph group trans to the leaving group also influences the overlap of frontier MOs which result in controlling the reactivity of the fluoro complexes. In general, the results show that the nature of the substituent, either electron withdrawing or electron donating, results in an increase in the rate of substitution. Second-order kinetics and large neg. activation entropies (¦¤S#) support an associative substitution mechanism. The exptl. data are supported by DFT calculations
Journal of Coordination Chemistry published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C3H8N2S, Recommanded Product: 1,1-Dimethylthiourea.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia