The synthesis and evaluation of a novel calix[4]arene-based fluorescent chemosensor 8 for the detection of Cd(2+) and Zn(2+) is described. The fluorescent spectra changes observed upon addition of various metal ions show that 8 is highly selective for Cd(2+) and Zn(2+) over other metal ions. Addition of Cd(2+) and Zn(2+) to the solution of 8 results in ratiometric measurement.

Research on single-molecule magnets (SMMs) has attracted intensive attention because of the intriguing physical properties associated with the quantum tunneling of magnetization effects and their potential applications in high-density information storage.[1] Since the slow magnetization relaxation in [Mn 12 O 12 (CH 3 COO) 16 (H 2 O) 4 ] (Mn12ac) was discovered, much effort has been made to fabricate metal-oxido clusters with the aim of generating properties analogous to those of the archetypical Mn 12 cluster. [2, 3] Recently, a giant Mn 84 cluster with a diameter of around 4 nm that exhibits SMM behavior was characterized structurally and magnetically. [4] Despite the high nuclearity of the Mn 84 supramolecular nanotube, its ground state (S) and energy barrier (U eff ) remain relatively small compared with the Mn12ac cluster. [4] Alternatively, cyanides are frequently utilized for the construction of high-spin molecules because of their structural and magnetic predictability.[5] To attain SMMs with cyanides, it would be a rational approach to combine) units as building blocks with magnetic anisotropy sources. In fact, when a metal ion with single-ion anisotropy is incorporated into a cluster, the magnetization at low temperatures relaxes slowly in some cases. [6, 7] Given that U eff is proportional to S 2 j D j for an integral spin state (D is the axial zero-field splitting parameter of a cluster), it is appropriate to seek high-spin clusters with negative values of D for the purpose of obtaining SMMs with increased values of U eff . Sizable high-spin ground states were established in octacyanidometallate-based M 9 M' 6 (M = Mn [8]

Primary arylamines are an important unit broadly found in synthetic, biological, and materials science. Herein we describe the development of a (NHC)Cu system that mediates a direct C-H amidation of (hetero)arenes by using N-chlorocarbamates or their sodio derivatives as the practical amino sources. A facile stoichiometric reaction of reactive copper-aryl intermediates with the amidating reagent led us to isolate key copper arylcarbamate species with the formation of a C-N bond. The use of (t)BuONa base made this transformation catalytic under mild conditions. The present (NHC)Cu-catalyzed C-H amidation works efficiently and selectively on a large scale over a range of arenes including polyfluorobenzenes, azoles, and quinoline N-oxides. Deprotection of the newly installed carbamate groups such as Boc and Cbz was readily performed to afford the corresponding primary arylamines.