Structural characteristics of some metallo-organic discogenst

We have recently analysed the crystal and molecular structures of six metalloorganic13; discogens with substituted {J-diketone ligands. The molecules consist of a rigid 11 atom core and a fringe made up of four phenyl rings substituted with13; alkyl/alkoxy chains. In complex (i),with four octyloxy chains, there are four oxygen atoms around the core. Complex (ii) is asymmetrically substituted with two13; heptyloxy and two heptyl chains and therefore has two oxygen atoms and complexes (iii) to (vi)have only alkyl chains and hence no oxygen atoms around the core. The metal atom used for coordination has been chosen as Cu/Pd/Ni. Determination of the crystal and molecular structures of these discogens has led to the identification of the following similarities: (1) All the six discogens crystallize in the triclinic space group PI. The recurrence of the space group may be correlated with the structural requirements for efficient packing of the molecules in the crystal lattice. (2) The coordination around the metal atom is square planar. (3) The 11 atom core is only nearly planar. (4)The phenyl rings and the chains are tilted with respect to the core. (5) The molecular conformation in the crystal confers a nearly13; rectangular shape to these discogens. (6)The chains are fully extended in an ail trans conformation. (7) The molecular arrangement is tilted columnar except for the13; crystal structure of complex (ii)

The Origin of Regioselectivity in a-Cleavage Reactions of Cyclopropenethiones: Potential Role of Pseudo-Jahn-Teller Effect in Substituted Cyclopropenyl Systems

Arylalkylcyclopropenethiones undergo highly regioselective photochemical a-cleavage via thioketene carbene intermediates, giving rise to products derived from the less stabilized carbene. UHF MIND0/3 calculations provide an insight into this unexpected regioselectivity. The nx* triplet of cyclopropenethione is calculated to have a highly unsymmetrical geometry with an elongated C-C bond, a delocalized thiaaUyl fragment, and a pyramidal radicaloid carbon (which eventually becomes the carbene center). From this molecular electronic structure, aryl group stabilization is expected to be more effective at the thiaallyl group rather than at the pyramidal radical center. Thus, the stability of the substituted triplet thione rather than that of the thioketene carbene determines the preferred regiochemistry of cleavage. The unusual structure of the cyclopropenethione triplet is suggested to be related to one of the Jahn-Teller distorted forms of the cyclopropenyl radical. An alternative symmetrical structure is adopted by the corresponding triplet of cyclopropenone, partly accounting for its differing photobehavior. A similar structural dichotomy is demonstrated for the corresponding radical anions as well

Effect of Zinc Fertilization on Zinc Transformations and Yield of Blakgram Grown in Inceptisols: A Case Study from India

A field experiment was conducted to study the effect of zinc fertilization on zinc transformation under blakgram crop grown on Inceptisols at Agricultural College Farm, Bapatla during Rabi, 2021. The experiment was laid out in a split plot design with three main treatments of zinc levels application (0, 25 and 50 kg Zn ha-1) and five sub treatments of blackgram varieties (LBG 752, LBG 787, TBG 104, GBG 1 and PU 31) replicated three times. The various Zn fractions viz., water soluble plus exchangeable Zn (WS+EX-Zn), organically complexed Zn(OCX-Zn), amorphous sesquioxide bound Zn(AMOX-Zn), crystalline sesquioxide bound Zn(CRYOX-Zn), residual Zn(Res-Zn) and total Zn were studied during different (pod development and harvest) stages of the crop. The results of experiment showed that the WS+EX-Zn, OCX-Zn, AMOX-Zn and CRYOX-Zncontent in soil significantly increased with increased levels of Zn application. Residual Zn was dominant fraction among all zinc fraction. Further, the concentration of WS+EX-Zn and OCX-Zn of soil significantly enhanced the yield of blackgram

2-methylperimidinium acetate monohydrate

The title compound, C12H11N2+.C2H3O2-.H2O, is a hydrated salt of 2-methylperimidinium acetate. The 2-methylperimidinium cations are protonated al the N atoms. In the acetate anions, the C-O bond distances are 1.238(3) and 1.265(3) Angstrom. A hydrogen-bonding network allows the self assembly of the ionic counterparts, together with the water of hydration, along the c axis