02383nas a2200241   4500008004100000022001400041245017700055210006900232260000800301300001100309490000800320520146400328653001501792653003001807653001301837653002301850653004501873100002101918700002201939700002701961700002501988856012802013       2019                        eng d  a1011-134400aEffect of substitution on the excited state photophysical and spectral properties of boron difluoride curcumin complex dye and their derivatives: a time dependent-DFT study0 aEffect of substitution on the excited state photophysical and sp  cOCT  a1115950 v1993 a<p>The optical, charge transport and electronic properties of boron difluoride curcumin (BFC) complex have been explored using the DFT (Density Functional Theory) method and B3LYP functional with the combination of 6-31 + G(d,p) as a basis set. The influence of substitution with various electron releasing and withdrawing groups on the above properties is analyzed and discussed in this work. The results reveal that the BFC complex on additional electron releasing substitution experiences redshifts in the optical transitions, and this is correlated with the dipole moment, NBO charges, HOMO-LUMO energy gap. Further, the absorption (lambda(abs)) and emission (lambda(ems)) spectra of substituted and unsubstituted BFCs are calculated using Time-Dependent Density Functional Theory (TD-DFT). The results show that the electron releasing groups strongly influence the absorption and emission spectra of BFC. Electron releasing groups in BFC derivatives generate the wavelength shift (Bathochromic), but the electron-withdrawing groups in BFC don't affect the lambda(abs) and lambda(ems) when compare to its original (parent) compound. The output of the research work strongly recommends that the amino, phenyl and N, N'-dimethylamino derivatives are potential candidates to act as fluorescent materials due to enhance the emission behavior of BFC and also can be used as an electron/charge transport material for organic light-emitting diodes (OLEDs).</p>
10aAbsorption10aBoron difluoride curcumin10aEmission10aMolecular orbitals10aTime-dependent density functional theory1 aSelvam, Karthick1 aGandhi, Sivaraman1 aKrishnarnurty, Sailaja1 aGopalakrishnan, Gopu  uhttps://library.ncl.res.in/content/effect-substitution-excited-state-photophysical-and-spectral-properties-boron-difluoride02882nas a2200277   4500008004100000022001400041245010200055210006900157260000800226300001100234490000800245520190900253653001502162653002802177653002202205653003602227653001502263653002302278653004502301100003102346700002102377700002602398700002602424700002502450856012902475       2020                        eng d  a1011-134400aTheoretical study on cyclophane amide molecular receptors and its complexation behavior with TCNQ0 aTheoretical study on cyclophane amide molecular receptors and it  cJAN  a1117350 v2033 a<p>Complexation behavior of cyclophane amide molecular receptors towards 7,7,8,8-tetracyanoquinodimethane (TCNQ) studied. TD-B3LYP/6-31 + G(d,p) based density functional theory was employed to investigate the photophysical characteristics of the complexes obtained. Syn isomers of cyclophane amide molecular hosts show preferred conformation over other conformations. Molecular Orbital analysis indicates the electronic structure change, which reflects in the absorption spectra of the cyclophane amide-1@TCNQ, and cyclophane amide-2@TCNQ charge-transfer (CT) complexes. Binding energy studies with B3LYP-D3/6-31 + G (d,p) theory demonstrated that the more effective binding of the pyridine-2,6-dicarboxamide macrocycles than for their isophthalamide analogs. Both the CT complexes show intermolecular bifurcated hydrogen bonding (N-H-(host)center dot center dot center dot N-(guest)center dot center dot center dot H-N-(host)) interactions (2.06 to 2.08 angstrom), and pi((host))center dot center dot center dot pi((guest)) interactions (3.2 to 3.4 angstrom). Calculated BSSE corrected complexation energy (Delta E) be associated with the formation of the inclusion complexes in the range - 28 to similar to 37 kJ mol(-1), indicating spontaneity of host-guest complex formation in both the cases. From the calculated vibrational spectra of these complexes, the formation of inclusion complexes via N - H-(host)center dot center dot center dot N-(guest) and pi((host))center dot center dot center dot pi((guest)) intermolecular interactions established by the frequency shift in the N - H vibrations. Mulliken population analysis performed to recognize the CT process and the variation in charges between the free and complex TCNQ molecules suggests the intermolecular charge transfer. This study indicates that these cyclophane amides can be a decent CT complexation host for the guests like TCNQ.</p>
10aAbsorption10aCharge transfer complex10aCyclophane amides10aElectrostatic potential surface10aHost-guest10aMolecular orbitals10aTime-dependent density functional theory1 aSundaram, Soma, Sundaram M1 aKarthick, Selvam1 aSailaja, Krishnamurty1 aKarkuzhali, Rajendran1 aGopu, Gopalakrishnan  uhttps://library.ncl.res.in/content/theoretical-study-cyclophane-amide-molecular-receptors-and-its-complexation-behavior-tcnq