A series of silylium cations [(R1R2R3Si)2H]+[B(C6F5)4]– (1–6) (1: R1 = R2 = R3 = Et; 2: R1 = R3 = H, R2 = Ph; 3: R1 = R3 = Me,...

No abstract

No abstract

A scandium dication active species [(IPr)­Sc­(μ-CH2SiMe3)­(μ-CH2CHMe2)­Al i Bu2]2+[B­(C6F5)4]2 – (IPr = (2,6-C6H3 i Pr2NCH)2C) in situ generated from the reaction of an N-heterocyclic carbene-ligated scandium trialkyl complex (IPr)­Sc­(CH2SiMe3)3 (2) with 1–3 equiv of cocatalyst [Ph3C]­[B­(C6F5)4] and an excess of Al i Bu3 exhibits unprecedentedly high activity (up to 2.2 × 106 g·molSc –1·h–1) and syndiotactic selectivity (rrrr > 99%) in the polymerization of o-methoxystyrene (oMOS) and its silyloxy- or fluorine-substituted derivatives, affording syndiotactic poly­(oMOS)­s and their silyloxy or fluorine-substituted derivatives with ultrahigh molecular weight (M n up to 4.6 × 106) and moderate molecular weight distributions (M w/M n = 1.37–2.21) unavailable by the traditional catalysts. Based on in situ NMR spectroscopy, matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) spectroscopy, and density functional theory (DFT) calculations, a plausible coordination polymerization mechanism has been proposed for the syndiotactic polymerization of oMOS by such a Sc dication active species.

The thiophene-modified rhodamine 6G (GYJ) has been synthesized as a novel chemosensor. The sensor has sufficiently high selectivity and sensitivity for the detection of Fe and Al ions (M) by fluorescence and ultraviolet spectroscopy with a strong ability for anti-interference performance. The binding ratio of M-GYJ complex was determined to be 2:1 according to the Job's plot. The binding constants for Fe and Al were calculated to be 3.91 × 10 and 5.26 × 10 M, respectively. All these unique features made it particularly favorable for cellular imaging applications. The obvious fluorescence microscopy experiments demonstrated that the probes could contribute to the detection of Fe and Al in related cells and biological organs with satisfying resolution. Graphical abstract GYJ has high selectivity and sensitivity for the detection of Fe(III) and Al(III) with the binding ratio of 2:1.