Synthesis, characterization and catalytic activity of peripherally tetra‐substituted Co(II) phthalocyanines for cyclohexene oxidation

Abstract

New 3,3-diphenylpropoxyphthalonitrile (5) was obtained from 3,3-diphenylpropanol (3) and 4-nitrophthalonitrile (4) with K 2 CO 3 in DMF at 50 C. The novel cobalt(II) phthalocyanine complexes, tetrakis- [2-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)ethoxy] phthalocyaninato cobalt(II) (2) and tetrakis-(3,3-diphenylpropoxy)phthalocyaninato cobalt(II) (6) were prepared by the reaction of the phthalonitrile derivatives 1 and 5 with CoCl 2 by microwave irradiation in 2-(dimethylamino)ethanol for at 175 C, 350 W for 7 and 10 min, respectively. These new cobalt(II)phthalocyanine complexes were characterized by spectroscopic methods (IR, UV-visible and mass spectroscopy) as well as elemental analysis. Complexes 2 and 6 are employed as catalyst for the oxidation of cyclohexene using tert-butyl hydroperoxide (TBHP), m-chloroperoxybenzoic acid (m-CPBA), aerobic oxygen and hydrogen peroxide (H 2 O 2 ) as oxidant. It is observed that both complexes can selectively oxidize cyclohexene to give 2-cyclohexene-1-ol as major product, and 2-cyclohexen-1-one and cyclohexene oxide as minor products. TBHP was found to be the best oxidant since minimal destruction of the catalyst, higher selectivity and conversion were observed in the products. a 2-Cyclohexen-1-ol. b 2-Cyclohexen-1-one. c Cyclolohexene oxide. d TON, moles of product/moles of catalyst. e TOF, moles of product/moles of catalyst  time.

Peripherally 1,2-dinaphthyl ethanediol substituted phthalocyanine complexes:synthesis, characterization, aggregation, and application in benzyl alcoholoxidation at room temperature

“…We found that increasing the oxidant to catalyst ratio from 100/1 to 200/1 led to the selective oxidation of benzyl alcohol to benzaldehyde with total conversion of 99% and 100% selectivity (TON = 198), but further increasing the oxidant ratio led to a decrease in the catalytic activity (up to 27%) (compare entries 1-7). These results support that in the presence of a higher amount of oxidant, the active sites of cobalt ion are blocked and this effect leads to the generation of inactive intermediate species during the catalytic reaction [31][32][33][34][35][36]. For the amounts of catalyst used influencing the results of the selective oxidation of benzyl alcohol, the effect of substrate to catalyst ratio was also investigated by varying from 200/1 to 1500/1 under optimized conditions ( Table 3).…”

The Effects of Asymmetry in Combination with Reduced Graphene Oxide Nanosheets on Hydrazine Electrocatalytic Detection on Cobalt Phthalocyanines

“…On the other hand, the Q-bands were observed at 663 and 661 nm for CoTPc and CoMPc respectively. Thus, the obtained Qbands are almost the same and in the range for CoPc [25,26].…”

Synthesis, electrochemistry of metal-free, copper, titanium phthalocyanines and investigation of catalytic activity of cobalt, iron phthalocyanines on benzyl alcohol oxidation bearing 4-{2-[3-trifluoromethyl)phenoxy]ethoxy} groups

“…The excess oxidant effects coordination around the ıron and cobalt ion and leads to the generation of inactive intermediate species. [37][38][39][40][41]. This study showed that only 500/1 ratio of oxidant/catalyst was needed for the reaction to get an optimum conversion of benzyl alcohol to reduced products.…”