Engineered organotin(IV) and vanadium(V) derivatives with distinct coordination modes and luminescent properties for the efficient detection and quantification of permanganate ions

The distinction in coordination modes of metal complexes leads to their versatile structural features and unique properties. Here, we report two tetradentate Schiff base ligands (H₂L¹ and H₂L²) bearing N₂O₂ donor sets, tactically selected to provide distinct coordination modes with different metal ions. The ligands were utilized to synthesize their organotin(IV) (1-4) and vanadium(V) (5) derivatives. The synthesized compounds were characterized using elemental analysis, FT-IR spectroscopy, multi-nuclei NMR (¹H, ¹³C, and ¹¹⁹Sn) spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. The organotin(IV) derivatives (1-4) displayed hepta-coordination around both the Sn centres as they were achieved in their dimeric form. Contrariwise, the vanadium(V) compound (5) was isolated as a mononuclear entity exhibiting penta-coordinated geometry around the vanadium centre. The variation in the coordination modes was evident in their UV-vis and fluorescence spectra. The organotin(IV) compounds (1-4) exhibited a strong emission band centred at 468 nm when excited at a wavelength of 360 nm whereas the vanadium(V) (5) derivative displayed poor fluorogenic response. Compound 1 was further explored for the fluorogenic chemo-sensing of permanganate ions (MnO₄^-) amongst various anions by quenching response. A detailed investigation of the recognition of permanganate ions was accomplished by spectrofluorometric, spectroscopic (¹¹⁹Sn NMR), mass spectrometric, and computational studies.

Extending Chirality in Group XIV Metallatranes

The syntheses of the racemic amino alcohol rac-N(CH₂CMe₂OH)(CMe₂CH₂OH)(CH₂CHMeOH) (L^22'1*H₃, 2) and its representative N(CH₂CMe₂OH)(CMe₂CH₂OH)(CH₂C(R)HMeOH) (L^22'1RH₃, 3) with the stereogenic carbon center being R-configured are reported. Also reported are the stannatranes L^22'1*SnOt-Bu (4) L^22'1RSnOt-Bu (6) and germatranes L^22'1*GeOEt (5) and L^22'1RGeOEt (7) as well as the trinuclear tin oxocluster [(μ₃-O)(μ₃-O-t-Bu){SnL^22'1R}₃] (8). NMR and IR spectroscopy, electrospray ionization mass spectrometry (ESI MS), and single crystal X-ray diffraction analysis characterize these compounds. Computational studies accompany the experimental work and help understand the diastereoselectivity observed in the course of the metallatrane syntheses.

3-Aminopropylsilatrane and Its Derivatives: A Variety of Applications

Silatranes arouse much research interest owing to their unique structure, unusual physical–chemical properties, and diverse biological activity. The application of some silatranes and their analogues has been discussed in several works. Meanwhile, a comprehensive review of the wide practical usage of silatranes is still absent in the literature. The ability of silatranes to mildly control hydrolysis allows them to form extremely stable and smooth siloxane monolayers almost on any surface. The high physiological activity of silatranes makes them prospective drug candidates. In the present review, based on the results of numerous previous studies, using the commercially available 3-aminopropylsilatrane and its hybrid derivatives, we have demonstrated the high potential of 1-organylsilatranes in various fields, including chemistry, biology, pharmaceuticals, medicine, agriculture, and industry. For example, these compounds can be employed as plant growth biostimulants, drugs, optical, catalytic, sorption, and special polymeric materials, as well as modern high-tech devices.

Water stable fluorescent organotin(iv) compounds: aggregation induced emission enhancement and recognition of lead ions in an aqueous system

Water stable fluorescent organotin(iv) compounds are investigated for their structural aspects, aggregation-induced emission enhancement (AIEE) properties and ability to recognize lead ions in the aqueous medium.

Mononuclear Pseudostannatranes Possessing Unsymmetrical [4.4.3.01,5]Tridecane Cage: Experimental and Theoretical Aspects of Reverse Kocheshkov Reaction in Phenyl Pseudostannatrane

The synthetic protocols, structural aspects, and spectroscopic aspects of mononuclear pseudostannatranes possessing a [4.4.3.0^1,5]tridecane cage have been reported. A tripodal ligand N(CH₂CH₂OH){CH₂(2-t-Bu-4-Me-C₆H₂OH)}₂ (H₃L) having unsymmetrical arms was reacted with n-butyltrichlorostannane, phenyltrichlorostannane, and tin tetrachloride under different solvent systems to obtain pseudostannatranes (1-3). The reaction of n-butyltrichlorostannane and the ligand in CH₃OH/Na/THF yielded an aqua complex of pseudostannatrane [LSnBu(H₂O)] (1_a), which was crystallized as its acetone solvate (i.e 1_a·Me₂CO). However, the same reactants yielded methanol complex [LSnBu(CH₃OH)] (1_b) when the reaction was carried out in the NaOCH₃/C₂H₅OH system. Similarly, the reaction of phenyltrichlorostannane and the ligand under these solvent systems yielded pseudostannatranes, i.e., an aqua complex [LSnPh(H₂O)] (2_a) and a methanol complex [LSnPh(CH₃OH)] (2_b) (where 2_a was crystallized as 2_a·Me₂CO). The reaction of tin tetrachloride and the ligand in the Et₃N/THF system resulted in the formation of pseudostannatrane [LHSnCl₂] (3). A similar product was isolated as its triethylamine solvate (3·NEt₃) due to the disproportion reaction when PhSnCl₃ was reacted with the ligand in the Et₃N/C₆H₅CH₃ system, which demonstrates the first report on the reverse Kocheshkov reaction in pseudostannatranes. The experimental findings on the formation of 3·NEt₃ due to the reverse Kocheshkov reaction have been corroborated with ¹¹⁹Sn NMR spectroscopy and density functional calculations that provide insightful information about the underlying details of the reaction route.