Crystal and molecular structure of 2,6-di (o-chloro)phenyl-3,5-dimethyl-N-nitrosopiperidin-4-one(NOCDMPO)

The title compound (C₁₉H₁₈O₂N₂Cl₂) crystallized in the monoclinic space groupP2₁/n witha=13.062(2),b=10.931(2),c=13.120(2)Å, and=104.57(1)°. The structure was solved by direct methods and refined toR=0.047 for 2776 reflections. The piperidine ring assumes a distorted boat conformation. The angle between phenyl rings is 78.98(7)°. The nitroso group is oriented by 138.22(7)° to the best plane of the piperidine ring. The interaction between the molecules are van der Waals in nature.DCB Contribution No. 814.     

Overall values of conventional discrepancy indices for crystals with heavy atoms. Part II. Results for monoclinic and orthorhombic crystals when the heavy-atom part alone constitutes the model

Theoretical expressions of 〈y _N〉, 〈|y _N − σ₁ y _P ^c |〉 and 〈|y _N ² −σ ₁ ² (y _P ^c )²|〉 (wherey _N andy _P ^c are the normalized structure amplitudes of the structure and the model respectively) are derived in terms of the heavy atom contributionσ ₁ ² for monoclinic and orthorhombic crystals containing a few (i.e., 1 or 2) heavy atoms of the same kind per asymmetric unit by taking the heavy atom part alone as the model. Results are obtained for both the related and unrelated cases. The local values of 〈y _N〉 and 〈|y _N ⁿ − σ ₁ ⁿ (y _P ^c ) ⁿ |〉, (n=1, 2) calculated from these expressions can be used to calculate the overall values of the conventionalR-indicesR(F) andR(I) for the related and unrelated cases. These overall values could be used to check the correctness of heavy atoms located in the structure. Contribution No. 550     

Synthesis of 7a‐aryl‐5‐t‐butyl‐3‐methyleneoctahydrobenzofuran possessing partial skelotons of some santonin analogue and furanolignans by intramolecular radical cyclisation reaction

Bicyclic octahydrobenzofuran derivatives ( 1c‐6c ) possessing the partial skeletons of santonin ( 7 ), 11,13‐dehydroisohyposantonin ( 8 ), dihydrosesamin ( 9 ) and lariciresinol ( 10 ) have been synthesised by intramolecular radical cyclisation in good yield via the precursors viz., the trans diaxial bromopropynyl ethers ( 1b‐6b ) obtained in highly regio/stereoselective manner.     

Microwave-assisted synthesis of naphthalenemonoimides and N-desymmetrized naphthalenediimides

Naphthalenemonoimides and N-desymmetrized naphthalenediimides were synthesized using a stepwise microwave-assisted protocol. The steric and electronic properties of aliphatic amines determined the outcome of the reactions, while in the amino acid series their ability to solubilize the naphthalene dianhydride starting material was crucial. Molecular modeling was used to rationalize the observed selectivity.     

High-PL efficiency of polyaniline using various dopants

Polyaniline (PANI) was doped with hydrochloric acid (HCl), succinic acid (C₄H₆O₄) and sulphuric acid (H₂SO₄) by chemical oxidation method. The samples were characterized by using various techniques such as XRD, photoluminescence IR and UV spectroscopy. FTIR study confirmed the presence of dopant molecules in the molecular structure. UV spectra revealed that absorption peaks at 350 nm and 600 nm are due to π–π* transition of polyaniline. The strong band at 600 nm showed extension of polymer chains in the prepared samples. XRD pattern confirmed the amorphous nature of polymer samples. The photoluminescence (PL) spectrum shows good emission at 490 nm. The intensity of photoluminescence depends upon the dopants nature.