Synthesis of highly fluorescent and water soluble perylene bisimide

Designed and synthesized a new highly water soluble N,N¹-bis（2-（（5-（（dimethylamino）methyl）furan-2-yl）methylthio）ethyl）-perylene -3,4,9,10-tetracarboxylic diimide from 2-（（5-（（dimethylamino）methyl）furan-2-yl）methylthio）ethanamine and perylene-3,4,9,10- tetracarboxylic dianhydride.The compound was characterized by ¹H,¹³C,2D NMR,mass and IR techniques.The compound is highly fluorescent with good solubility in water and other polar solvents.     

Structural elucidation of transition metal complex by single crystal EPR study

Single crystal EPR studies of Mn(II) doped hexaaquazincdiaquabis(malonato) zincate [Zn(H₂O)₆][Zn(mal)₂(H₂O)₂] have been carried out at room temperature using X-band spectrometer to identify the location of the dopant. Single crystal rotations along the three orthogonal axes show more than 30 line pattern EPR spectra indicating the presence of two types of dopant ions in the host lattice, with intensity ratio of 6:1. However, the latter could not be followed due to its low intensity during crystal rotations. The spin-Hamiltonian parameters, estimated from the three mutually orthogonal crystal rotations are: g_xx = 1.972, g_yy = 2.000, g_zz = 2.023, A_xx = 8.95, A_yy = 9.48, A_zz = 9.93 mT, D_xx = −34.49, D_yy = −3.26, D_zz = 37.74 mT and E = 15.6 mT. The direction cosines of one of the principal values of g match with that of Zn-O bond in the host lattice, suggesting that the Mn(II) ion entered the lattice substitutionally. The large value of E is indicative of low symmetry of the substitutional site, in accordance with the crystal structure of the isomorphous [Zn(H₂O)₆][Cu(mal)₂(H₂O)₂]. Covalency of Mn-O bond, estimated from Matamura’s plot, is 9%. Various admixture coefficients, bonding and optical parameters have also been calculated.     

Self-assembly,optical and electrical properties of fork-tailed perylene bisimides

Effect of side-chain length on self-assembly, optical and electrochemical properties of N,N′-di(1-pentylbutyl)perylene-3,4,9,10-tetracarboxylic bisimide and N,N′-di(1-hexylpentyl)perylene-3,4,9,10-tetracarboxylic bisimide has been studied. The photo-physical, thermal and electrochemical properties were studied using UV–Vis and fluorescence, differential scanning calorimetry, and cyclic voltammetry, respectively. The molecules self-assembled as 1D – rods and molecular bundles, self-assembly was studied using SEM, optical and fluorescence microscopic techniques. The results concluded that the compound with short tail exhibits low solubility and self-assembled faster. The photo-physical properties of the compounds were not much affected by varying the alkyl chain length. The compounds geometries were optimized at 6-31G^∗ using DFT and the potentials were correlated with molecular orbitals.     

Structural elucidation of Cu(II) ion doped in hexaaquozincdiaquobis(malonato)zincate host by EPR spectroscopy

In order to understand the structural behaviour of Cu(II) in a variety of ligand environments, single crystal electron paramagnetic resonance studies of Cu(II) doped in hexaaquazincdiaquabis(malonato)zincate [Zn(H₂O)₆][Zn(mal)₂(H₂O)₂] are carried out at 300 K. Angular variation of copper hyperfine lines in three orthogonal planes shows the presence of single site, with spin Hamiltonian parameters as g_xx=2.034, g_yy=2.159, g_zz=2.388, A_xx=3.39 mT, A_yy=4.89 mT and A_zz=13.72 mT. The g/A tensor direction cosines are compared with various Zn-O directions in the host lattice, which confirm that Cu(II) enters substitutionally in the lattice. The low value of A_zz has been explained by considering admixture of d_²x−²y ground state with d_²z excited state. EPR powder spectra at 300 and 77 K give identical spin Hamiltonian parameters (g_∥=2.367, g_⊥=2.088, A_∥=11.47 mT, A_⊥=2.63 mT). IR, UV-vis and powder XRD data confirm the structure and symmetry of the Cu(II) ion in the host lattice.     

Identification of Structure and Position of Cu(II) Ion in Aquomethylmelonatozinc(II) Host by Powder XRD, EPR, FT-IR and UV–Vis Spectroscopy

Single-crystal electron paramagnetic resonance studies of Cu(II)-doped aquomethylmelonatozinc(II) are carried out at 300 K. Angular variation of copper hyperfine lines in the three orthogonal planes shows the presence of a single site in substitutional position, with spin Hamiltonian parameters: g ₁₁ = 2.076, g ₂₂ = 2.100, g ₃₃ = 2.379; A ₁₁ = 2.40 mT, A ₂₂ = 3.22 mT and A ₃₃ = 13.47 mT. The low value for the hyperfine structure parameter value for A ₃₃ has been explained by taking into account a considerable admixture between d_{x² - y²} d_{{x^{2} - y^{2} }} ground state and d_z² d_{{z^{2} }} excited state, with admixture coefficients being a = 0.291, b = 0.951, c = 0.054, d = 0.031 and e = −0.031, where coefficients a and b correspond to coefficients for d_z² d_{{z^{2} }} and d_{x² - y²} , d_{{x^{2} - y^{2} }} , respectively. Few other calculated parameters such as κ = 0.35, P = 303 × 10⁻⁴ cm⁻¹; α = 0.88 and α′ = 0.47 indicate considerable covalency. Powder X-ray diffraction, Fourier transform infrared and ultraviolet-visible data confirm the structure of host complex and presence of the dopant.     

Camphor-based Schiff base ligand SBAIB: an enantioselective catalyst for addition of phenylacetylene to aldehydes

A series of Schiff base ligands were synthesized from (1R)-camphor. Under the optimal conditions, (+)-SBAIB-a, 10 was found to be an excellent catalyst for the enantioselective addition of phenylacetylene to various aldehydes without utilizing either achiral additives or Ti(O(i)Pr)(4). This approach yielded (R)-propargylic alcohols in extremely high yields (up to 99%) and excellent enantioselectivities (up to 92%). The corresponding (S)-propargylic alcohols were synthesized in good to high enantioselectivities (up to 91%) and excellent yields (up to 99%) using (-)-SBAIB-a, 41.     

Effect of paramagnetic doping on an inorganic polymer triaquadipotassiumbis(malonato)zincate: spectroscopic investigation

Spectroscopic investigations on Mn(II)-doped triaquadipotassiumbis(malonato)zincate [K₂(H₂O)₃] [Zn(mal)₂], an inorganic polymer, have been carried out at room temperature using single crystal electron paramagnetic resonance (EPR), ultraviolet–visible, FT-IR and powder XRD techniques. Single crystal rotations along the three orthogonal axes show more than 30 lines of patterns in EPR spectra, indicating the presence of two sites, one with a large D value and the other with a smaller D value. The calculated spin-Hamiltonian parameters are as follows. Site 1: g _xx =2.099, g _yy =2.092, g _zz =1.988, A _xx =9.77, A _yy =9.71, A _zz =8.96 mT, D _xx =?29.09, D _yy =?11.90, D _zz =40.99 mT; Site 2: g _xx =2.040, g _yy =1.995, g _zz =1.924, A _xx =9.51, A _yy =9.09, A _zz =8.80 mT, D _xx =?11.94, D _yy =?7.51 and D _zz =19.45 mT. The direction cosines of g/A/D do not match with the direction cosines of Zn–O bonds in the host lattice for either site, suggesting that both the Mn(II) sites entered the lattice interstitially. Optical results indicate a strong covalent bonding between the metal ion and ligands, with site symmetry being primarily octahedral. The FT-IR and powder XRD data confirm the retention of the crystal structure, even after incorporating a paramagnetic probe. Various admixture coefficients, bonding and optical parameters have also been calculated.     

A Proficient approach to enhance heat transfer using cupric oxide/silica hybrid nanoliquids

Journal of Thermal Analysis and Calorimetry - High performance cooling anticipated in smaller size heat transfer equipment is the most significant challenge in many industries including CPU...     

A convenient and practical synthesis of olmesartan medoxomil methyl ether

Synthesis of Olmesartan medoxomil methyl ether ( 2 ), a potential impurity of Olmesartan medoxomil ( 1 ), an angiotensin II receptor blockers is reported for the first time.     

Spectroscopic Study of Cu(II) Ion Doped in Bis-Glycine Sodium Nitrate

Single-crystal Electron Paramagnetic Resonance (EPR) and optical absorption studies were performed at room temperature on Cu(II)-ion–doped bis-glycine sodium nitrate, a semiorganic nonlinear optical material (NLO). Spin-Hamiltonian parameters, obtained from single-crystal EPR spectra, recorded in three mutually orthogonal planes, revealed the presence of two magnetically inequivalent Cu(II) sites. Molecular orbital parameters were also evaluated. The optical absorption spectrum at room temperature exhibits the lowering of octahedral symmetry to an axially elongated tetragonal of Cu(II) ion in NLO.