The first reported syntheses and characterisation of alkali metal trifluoronickelate(II) monohydrates,MNiF3 · H2O (M = NH4, Na or K)

Summary Ni(acac)₂ · (H₂O)₂ (1 mol) and alkali metal fluorides (4 mols), MF (M=NH₄, Na or K), react with an excess of 40% HF on a steam-bath. The product upon treatment with water gives light green crystalline alkali metal trifluoronickelate(II) monohydrate, MNiF₃ · H₂O in a high yield. Chemical analyses, pyrolysis at 120 °C, i.r. spectroscopic, and cryomagnetic (300–80 K) data have been used to characterise, and establish the identity of the compounds. While NH₄NiF₃ · H₂O behaves as a normal octahedral nickel(II) compound, NaNiF₃ · H₂O is ferromagnetic with Curie point 145 K, KNiF₃ · H₂O behaves antiferromagnetically; its Neel point is 230 K.     

Optical and magnetic properties of manganese-incorporated zinc sulfide nanorods synthesized by a solvothermal process

Manganese-incorporated ZnS (MnxZn1-xS) nanorods were synthesized by a simple solvothermal process. Synthesized nanorods were single crystalline. Manganese incorporation in the ZnS lattice induces a phase transformation from hexagonal wurtzite to cubic zinc blende structure. The diameter of the nanorods increased with the increase of Mn concentration. Intense orange luminescence at approximately 585 nm was observed for the nanorods. Six-line hyperfine splitting was observed in the EPR spectra for lower Mn concentrations, whereas broad Lorentzian-shaped EPR spectra were obtained for higher Mn concentrations because of the Mn-Mn cluster formation at higher Mn concentrations.     

Studies on indian medicinal plants,part LXXIX : Synthesis proves the structure of aristolindiqu inone

Aristolindiquinone ($\text{1}$) , the first naturally occurring 8-methyl-juglone earlier isolated from $\text{Aristolochia indica}$ has been synthesised from $\text{o}$-allyl-$\text{p}$-cresol in 7% overall yield.     

Synthesis,physico-chemical and antimicrobial studies on acetylferrocenyl hydrazone derivatives of dichlorobis(cyclopentadienyl)hafnium(IV)

The reactions of Cp₂>HfCl₂> with hydrazones (LH) derived from acetylferrocene and aromatic acid hydrazides (benzoic, 2-chlorobenzoic, 3-nitrobenzoic and 4-toluic) in various stoichiometric ratios have been studied and the complexes of the types [Cp₂>Hf(L)Cl] and [CpHf(L)₃>] were obtained. Tentative structural conclusions are drawn for the reaction products based upon elemental analyses, electrical conductance, magnetic moment and spectral data (u.v.–vis, i.r., ¹>H-n.m.r. and ¹³>C-n.m.r.). Studies were conducted to assess the growth-inhibiting potential of the complexes synthesized, and the ligands, against various fungal and bacterial strains.     

Rapid assembly of the functionalized tricyclic core of umbellactal through domino metathesis involving ROM-RCM of a norbornene derivative

A novel approach to the construction of the functionalized core structure of the anticancer diterpene umbellactal is described using a domino metathesis protocol involving ROM-RCM of an appropriately constructed norbornene derivative.     

Role of Emissive and Non‐Emissive Complex Formations in Photoinduced Electron Transfer Reaction of CdTe Quantum Dots

Bimolecular photoinduced electron transfer (PET) from excited state CdTe quantum dot (QD*) to an electron deficient molecule 2,4‐dinitrotoluene (DNT) is studied in toluene. We observed two types of QD‐DNT complex formations; (i) non‐emissive complex, in which DNT is embedded deep inside the surface polymer layer of QD and (ii) emissive complex, in which DNT molecules are attached to QDs but approach to the QD core is shielded by polymer layer. Because of its non‐emissive nature, the lifetime of QD is not affected by dark complex formation, though the steady‐state emission is greatly quenched. However, emissive complex formation causes both, lifetime and steady‐state emission quenching. In our fitting model, consideration of Poisson distribution of the attached quencher (DNT) molecules at QD surface enables a comprehensive fitting to our time resolved data. QD‐DNT complex formation was confirmed by an isothermal titration calorimetry (ITC) study. Fitting to the time resolved data using a stochastic kinetic model shows moderate increase (0.05 ns^?1 to 0.072 ns^?1) of intrinsic quenching rate with increasing the QD particle size (from ≈3.2 nm to ≈5.2 nm). Our fitting also reveals that the number of DNT molecules attached to a single QD increases from ≈0.1–0.2 to ≈1.2–1.7, as the DNT concentration is increased from ≈1 mm to 17.5 mm . Complex formation at higher quencher concentration assures that the observed PET kinetics is a thermodynamically controlled process where solvent diffusion has no role on it.     

Regioselective Synthesis of Fused Furans by Decarboxylative Annulation of α,β‐Alkenyl Carboxylic Acid with Cyclic Ketone: Synthesis of Di‐Heteroaryl Derivatives

α,β‐Alkenyl carboxylic acids undergo Cu^II‐mediated decarboxylative annulation reactions with aliphatic cyclic ketones to provide synthetically valuable di‐heterocycles. The annulation process tolerates a variety of aliphatic ketones and heterocyclic alkenyl carboxylic acids, producing substituted fused furan derivatives with complete regioselectivity. The current protocol offers a synthetically applicable pathway to construct a variety of oligo‐heterocycles through Cu‐mediated single‐electron transfer and decarboxylation. Notably, synthesis of relatively inaccessible di‐heterocycles has been achieved successfully using this protocol.     

Parity violation in a gravitational theory with torsion: A geometrical interpretation

In a space-time with torsion, the action for the gravitational field can be extended with a parity-violating piece. We show how to obtain such a piece from geometry itself, by suitably modifying the affine connection so as to include a pseudo-tensorial part. A consistent method is thus suggested for incorporating parity-violation in the Lagrangians of all matter fields with spin in a space-time background with torsion.     

Studies in sulphur heterocycles. Part 7 . Tricyclic compounds related to 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene

Synthesis of a number of tricyclic compounds with a fused thiophene ring starting from 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-4-one and benzosuberone is described. Biological testing of these compounds for their antiparasitic activities has been carried out.