Experimental and theoretical magnetostructural studies on discrete heterometallic cyanide-bridged dinuclear FeIIIMnII and tetranuclear FeIII2CuII2 complexes bearing tripodal pyrazolyl borate and tetradentate phenolate-based ligands.

Two new complexes [FeIII(Tp)(CN)2(µ-CN)MnIICl(HL1)]·3DMF (1) and {[FeIII(Tp)(CN)(µ2-NC)2CuII(HL2)](ClO4)}2·6DMF (2) (HL1 = 2-((((1-methylbenzimidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenol and HL2 = 2-(((pyridin-2-ylmethyl)(quinolin-2-ylmethyl)-amino)methyl)phenol) have been synthesized and characterized by elemental analysis and IR and UV/vis spectroscopy. Structural analysis revealed that 1 is a discrete dinuclear coordination complex and 2 is a discrete tetranuclear coordination complex. In complex 1, each MnII is in a distorted octahedral MN4OCl environment where coordination is satisfied by three nitrogen atoms and one oxygen atom of the ligand, and a chloride group and one nitrogen atom from cyanide. In complex 2, each Cu is in a distorted octahedral MN5O environment where coordination is satisfied by three nitrogen atoms and one oxygen atom of the ligand, and two nitrogen atoms from two cyanides. Direct current (dc) variable-temperature magnetic susceptibility measurements on polycrystalline samples of 1 and 2 were carried out in the temperature range of 1.8-300 K. Investigation of the magnetic properties reveals the occurrence of weak antiferromagnetic coupling between the low-spin FeIII (S = 1/2) ions and high-spin MnII (S = 5/2) ions in 1, while 2 exhibits ferro- and antiferromagnetic coupling between the metal ions in the tetranuclear CuII2FeIII2 unit. DFT calculations show ferromagnetic coupling in both complexes, although this appears to be weak in the case of complex 1. In addition, magnetostructural correlations reveal the magnetic behavior against Mn-N-C and Fe-C-N angles in 1 and Cu-N-C and Fe-C-N angles in 2.

Design, Synthesis, and Applications of a Vanadium Complex: An Effective Catalyst for the Direct Conversion of Alcohols and Aldehydes to Esters.

A novel bench-stable V-catalyst [(L2)VIVO](ClO4) was synthesized and characterized by X-ray diffraction (XRD) analysis and FT-IR, UV-visible, and EPR spectroscopies, which confirmed its excellent catalytic activity. In application, aldehydes are rapidly converted into their corresponding esters without additives in a one-pot manner using a newly developed catalyst [(L2)VIVO](ClO4) and H2O2 as a green oxidant. The developed method is compatible with a broad range of densely substituted aldehydes and allows for the facile preparation of aliphatic, aromatic, and heterocyclic esters, including esters derived from CD3OD, methanol, ethanol, iso-propanol, n-butanol, sec-butyl alcohol, and propargylic alcohol. Gratifyingly, numerous alcohols also directly converted to their corresponding esters in a one-pot manner. We disclose herein the direct conversion of two different functionalities (alcohols and aldehydes) into esters (33 examples) with satisfactory yields, showing the potential of the developed catalyst toward varied oxidative organic transformations in a one-pot manner.

Ring-Opening Cyclization (ROC) of Aziridines with Propargyl Alcohols: Synthesis of 3,4-Dihydro-2H-1,4-oxazines.

Activated aziridines react with propargyl alcohols in the presence of Zn(OTf)2 as the Lewis acid catalyst following an SN2-type ring-opening mechanism to furnish the corresponding amino ether derivatives. Those amino ethers further undergo intramolecular hydroamination via 6-exo-dig cyclization in the presence of Zn(OTf)2 as the catalyst and tetrabutylammonium triflate salt as an additive under one-pot two-step reaction conditions. However, for nonracemic examples, ring-opening and cyclization steps were conducted under two-pot conditions. The reaction works well without any additional solvents. The final 3,4-dihydro-2H-1,4-oxazine products were obtained with 13 to 84% yield and 78 to 98% enantiomeric excess (for nonracemic examples).

Mounting a smartphone on a steering-wheel to facilitate ease of visibility of the navigation screen: A systematic product design approach.

BACKGROUND: Both professional and personal car drivers use smartphones as In-Vehicle Infotainment System (IVIS) and generally mount it wherever they feel convenient. Inappropriate or sub-optimal positioning of navigation devices increases off-road eye-glance duration and fixation frequency. OBJECTIVE: The current research aimed to develop a smartphone holding device to facilitate the mobile-phone's easy mounting on the steering wheel's hub, ensuring the screen's visibility at a comfortable viewing angle in a vertical upright position irrespective of the steering wheel's rotation. METHODS: A systematic product design methodology was adopted to develop the final product. The morphological chart was adopted for generating the different concepts of the smartphone mounting device. A Pugh chart was used for screening the various concepts generated in the previous step. Finally, a prototype of the selected best concept was made. User acceptance was assessed by taking feedback from users, and System Usability Scale (SUS) was used for usability evaluation. RESULTS: The developed innovative mounting device was light-weight and easy to use (SUS score 83.5). The final prototype was very effective in changing the angle of the smartphone to facilitate easy visibility at a comfortable viewing angle through the use of a ball and socket mechanism at the base. A ball bearing system was used in the mobile-phone holder for maintaining vertical stationary position during steering wheel rotation. CONCLUSION: As the device is useful for mounting the smartphone on the steering wheel's hub, it might reduce driver distraction.