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Urethane imide anhydride oligomers with terminal groups as anhydride groups were designed and synthesized using second-order nonlinear optical chromophore molecule, bisphenol AF-type diethylidene dianhydride, and toluene diisocyanate as monomers. Polyurethaneimide (PUI) second-order nonlinear optical polymers with the structure of imide and amino ester chain segments were then synthesized by the polycondensation reaction between urethane imide anhydride oligomers and aromatic diamine monomers. The glass transition temperature ([T.sub.g]) of PUI reached 186[degrees]C, and the 5% heat-loss decomposition temperature was 320[degrees]C. The corona-polarized PUI had an electro-optic (EO) coefficient ([[gamma].sub.33]) of 82 pm/V tested by the reflection method. The loss of light transmission of the polymer waveguide prepared with PUI as electro-optical material was 1.13 dB/cm at 1550 nm. Mach-Zehnder type polymer waveguide electro-optical modulators have been prepared based on the properties of the electro-optic material PUI. The fabricated polymer EO modulators had favorable electro-optic modulation response performance for lowfrequency electrical signals. The good modulation characteristics of the manufactured electro-optical modulators proved that the synthesized PUI was a waveguide polymer material with good comprehensive performance. Highlights * Electro-optic fluorinated polyurethaneimide was synthesized. * Polyurethaneimide as core material, polymer waveguide EO modulators were fabricated. * The prepared modulators had good electro-optic modulation performance. KEYWORDS electro-optical materials, performance, polyurethaneimide, synthesis, 1 | INTRODUCTION Optically favorable second-order nonlinear optical (NLO) polymeric materials have received much attention for their application in the manufacture of electro-optical waveguide devices. (1-3) EO modulators are indispensable [...]

The electrochemical analysis, spectroscopy, and electrogenerated chemiluminescence (ECL) of four monodisperse star-shaped truxene core-oligofluorene compounds are described. The oligomers demonstrate electrochemistry in a MeCN/Bz solution with fair stability of both anion and cation radicals.

The electrochemical and electron transport properties of self-assembled monolayers (SAMs) of a molecular wire candidate, 1-thio-4-[(4'-thio)phenylethynyl]-1'-ethynyl]-2',5'-(diethyl)phenylbenzene (TTEB) is examined by anodic stripping voltammetry of copper. Electrochemical copper deposition suggests that the SAMs of TTEB passivate the electrode to electrochemistry similar to alkanethiols.

Several reactions are conducted for the development of a series of various six-ring oligothiophenes containing one to three degrees of ring fusion. The different effects of position and extent of ring fusion on the electronic properties of the compounds are also explained.

A series of linearly linked perylenediimide (PDI) dimers and trimers are prepared and the intramolecular electron hopping between the PDI molecules is probed by using electron paramagnetic resonance (EPR) spectroscopy. The rapid electron hopping between pairs of PDI molecules having orthogonal [pi] systems has helped in expanding the design motifs for organic electronic materials based on PDI.

Three discrete oligomeric systems including an all-thiophene system, a thiophene/phenylene (TPTTPT) system, and a thiophene/EDOT/phenylene (TPEEPT) system are constructed and their structural, optical and electrochemical properties are characterized. A simple photopatterned electrochromic device is constructed by using the terminal acrylate functionalities of the oligomers in an ultraviolet-initiated cross-linking process.

An implementation of mixed quantum/classical molecular dynamics simulation was utilized to study the ground and excited state dynamics of poly(p-phenylenevinylene) (PPV) chains. Very slight preference for a more planar conformation in the excited state compared to the ground state is observed.

Several techniques are employed together for directly measuring the intersystem crossing (ISC) rate and triplet decays of luminescent conjugated oligomers in solutions. The analysis reveals that the triplet state lifetime increases very rapidly, as compared to the room temperature.

The study about the ion radicals of two series of platinum acetylide oligomers conducted by employing electrochemical and pulse radiolysis/transient absorption methods is presented. Results suggest that the polarons are delocalized to some extent on the platinum acetylide chains.

The electronic structures of two series of end-capped thiophene oligomers are modeled by using semiempirical quantum chemical calculations and the results used to assign features in the photoemission spectra of the materials in the condensed phase. It is shown that in the thiophene oligomers end-capped with the electron-deficient dimesitylboryl moieties the energy of the occupied frontal orbitals is governed by [pi]-type orbitals of the thiophene repeat units in the oligothiophene main chain.

The synthesis of new ternary zintl compounds L[i.sub.2]L[n.sub.5]S[n.sub.7] (Ln = Ce, Pr, Sm, Eu) is presented. The compound contains isolated S[n.sub.7] oligomers that resemble carbon core of an open-chain normal heptane molecule, n-[C.sub.2][H.sub.16].

Both homo- and heterosequence m-phenylene ethynylene oligomers are synthesized using a conceptually simple interative solid-phase strategy. The method is found to considerably reduce the time required for the construction of phenylene ethynylene oligomers, which in turn would allow for a more in-depth investigation into their sequence variations.

An experiment is carried out to measure the single chain elasticity of an oligomer single-stranded DNA (ssDNA) in both aqueous and nonaqueous, apolar liquid environment by AFM-based single molecule force spectroscopy. The experimental results suggest that the weak H-bonding between ssDNA and water molecules might be a precondition for stable double-stranded DNA to exist in water.

Ab initio Hartree-Fock calculations are used to obtain the electronic structure and the frequencies of normal vibrations in the 1:1:1 solid polymer electrolytes CH3(OCH2CH2)2OCH3-M(super +)-X(super -) (M=Li, Na, and K and X=Cf3So3, PF6, and (CF3SO2)2N). These calculations predict stronger binding for the lithium ion toward the ether oxygens of diglyme in these electrolytes.

The geometric and electronic structures of poly(9,9-dicotylfluorene) (PFO) oligomer interacting with Ca atoms are studied. The geometric and electronic structures of complexes between PFO and Ca are revealed by studying their different interactions.

A study was conducted to bring together the areas of supramolecular assembly and pi-conjugated systems. It was clearly shown that successful implementation of self-assembled pi-conjugated systems in electronics depended on the other layers and electrodes present in the devices largely.

The facile synthesis of oligomers of hexa-peri-hexabenzocoronene (HBC), up to trimers (3,4, 5a-c) with different modes of connection is presented and a methylene-bridged HBC dimer, so-called 'superfluorene' was prepared for comparison. The induced planarity improves pi-conjugation and suppresses the geometrical relaxation of the backbone upon electronic excitation, leading to a prominent 0-0 transition band in the fluorescence spectra.

The nonlinear optical properties of polyaminoborane and polyiminoborane oligomers are studied by using ab initio schemes taking explicitly into account the dynamic electron correlation effects. The geometry, charges, dipole moments, polarizability and first hyperpolarizability of polyaminoborane and polyiminoborane are investigated.

Site-specific cross-coupling reactions used to prepare an introductory series of conjugated siloleneethynylene co-oligomers from a key 2-chloro-5-iodosilole intermediate is reported. The long wavelength absorptions shown by these relatively short oligomers imply electronic behavior similar to that of silole polymers.

The kinetics for photoinduced charge separation and recombination in the triads is studied. Intramolecular photoinduced electron transfer is observed in three fullerene-donor-fullerene (ADA) triads that contain and electron-rich pyrrole ring in the donor moiety.

Suitably difunactionalozed oligomers are used to synthesize a series of novel, soluble and strongly fluorescent C60-conjugated oligomer triads through 1,3-dipolar cycloaddition reactions. The nature of the oligomeric components is modified to create the absorption wavelength of the chromophore as well as the oxidationpotential of the olgomeric donor moiety.

The first ab initio calculation results for the electronic and structural properties for phenyl-substituted octahydrosilsesquioxanes (H8Si8O12) is presented. The results show that the orbitals near the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) for the phenyl-substituted polyhedral oligomeric silsequixoane (POSS) clusters and crystal are localized on the phenyl rings.

The analysis of chain length dependence of the electronic, electrochemical, and vibrational properties of the three series of oligomers is carried out using cyclic voltammetry and Raman spectroscopies. The results show that incorporation of ethylenic linkages in an oligothiophene structure leads to faster decrease of the HOMO-LUMO gap with chain extension due to the combined effects of enhanced planarity and lower overall aromatic character of the system.

The electroabsorption (Stark) spectroscopy is used to determine the trace of the change in polarizability and the absolute value of the change in dipole moment of the electroluminescent polymer poly[2-methoxy,5-(2'-ethyl-hexoxy)-1,4-phenylene vinylene) (MEH-PPV) and related oligomers in solvent glass matrixes. A value of change in polarizability is found of ~2000 angstrom (super 3) for the polymer and for a 9-ring substituted oligomer in both toluene and 2-methyl tetrahydrofuran mixtures at 77 K with smaller values being obtained fro 3- and 5-ring unsubstituted oligomers.

The examination of the geometric and electronic structures of oligothiophene dications (with 6 to 12 monomers) is presented using the spin-unrestricted broken symmetry hybrid density functional B3LYP method. The results reveal that there exists a transition region of bipolaron to two-polaron structure conversion in the moderately sized oligomers.

Geometry optimizations and fragmentation energies of the series of hydrogen cyanide borane (1) oligomers (up to hexamers) and their dehydrogenated analogues are examined. It is concluded that the stability of the oligomers in terms of initial 'cracking' of the weakest bond is fairly high, ranging from 97 to 443 kJ/mol for the HCNBH series and from 329 to 589 kJ/mol for the HCNB series.

Polyacenes are polycyclic aromatic hydrocarbons consisting of linearly fused benzene rings. The electronic properties of large oligoacenes are theoretically presented.

The electrochemical detection of a hybridization event by electrostatic modulation of ion-exchange kinetics of polypyrrole film is described. It is shown that the ion exchange is controlled by unlabeled, single-stranded DNA oligomer molecule that is linked to the conducting polymer.

A new series of platinum-acetylide oligomers has been synthesized by an iterative-convergent approach. Absorption and photoluminescence spectroscopy of the oligomers provide considerable insight into the extent of delocalization in the singlet and triplet excited states in Pt-acetylide materials.

Two mechanisms are responsible for the changes in impedance of single molecules and these are the relative motion of the molecule internal structures and the changes in the molecule charge states. Experiments were conducted using the scanning tunneling microscopy to know more about the conductance switching in phenylene ethylene oligomers isolated in matrices of dodecanethiolate monolayers.