An efficient and eco-friendly method is reported for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from the direct cyclocondensation of anthranilamide with aldehydes using psulfonic acid calix[4]arene (p-SAC) as a recyclable organocatalyst in excellent yields in water at room 10 temperature. The catalyst was reusable without significant loss of catalytic efficiency. Operational simplicity, the compatibility with various functional groups, nonchromatographic purification technique, high yields and mild reaction conditions are the notable advantages of this 15 procedure. Large scale reaction demonstrated the practical applicability of this methodology.
Most of transition metal(II) carboxylates were reported to exist as multinuclear complexes due to the multibinding modes of the ligands 1,2. For example, most of the copper(II) carboxylates were dinuclear with the paddle-wheel structure 3-7 , while other metal(II) complexes (Mn, Co, Ni and Zn) were found to form polymeric structures 8-11. Hence, these complexes are attracting the interests of many researchers in various fields, such as catalysis, molecular electronics and molecular magnetism. The main reason is because they are easily prepared from relatively low cost, nontoxic and readily accessible starting materials and readily characterized by conventional analytical methods. However, these complexes are yet to be commercially used as functional materials due to physical limitations, such as insolubility, high-melting and low-decomposition temperatures. Currently, our research group is focused on designing, synthesizing and characterizing thermally stable and low melting temperatures magnetic metal(II) carboxylates to function as molecular magnetic, photonic and electronic materials and as precursors for functional coordination polymers. This paper reports the synthesis, structural, magnetic, thermal, optical and redox properties of three complexes of 2-hexyldecanoato ligand (L) with Cu(II) (1), Ni(II) (2) and Co(II) (3). These complexes were obtained as room-temperature viscous liquids from the reaction of NaL with the
2 O (3), where L [12][13][14][15][16] are N 3 -Schiff bases appended with linear C 12-16 carbon chains at the nitrogen atoms, were obtained in good yields by facile one-pot reactions. The single crystal X-ray structure of complex 1 shows a tetragonally compressed CoN 6 coordination geometry. The melting temperatures of 1 -3 were lower than 373 K, while their decomposition temperatures were above 473 K. All complexes have high-spin Co(II) centres at 300 K and exhibit a columnar mesophase above 383 K. Complexes 1 and 3 showed a normal thermal spin-crossover behaviour with weak hysteresis loops at about 320 K. Hence, these complexes showed uncoupled phase transitions (class iiia). 1 The values for the Seebeck coefficient (S e ) of the cobalt redox couples formed from 1 and 2 were 1.89±0.02 mV K -1 and 1.92±0.08 mV K -1 , respectively, identifying them as potential thermoelectrochemical materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.