The challenge of cyclic and acyclic schiff bases and related derivatives

Organometallic molecular wires and other nanoscale-sized devices: An approach using the organoiron (dppe)Cp*Fe building block

Di- and polymetallic heteroatom stabilized (Fischer) metal carbene complexes.

The chemistry of binuclear palladium(II) and platinum(II) complexes

Four series of dyes with dimethylamino electron donor groups and N-R-pyridinium (R = methyl Me, phenyl Ph, 2,4-dinitrophenyl 2,4-DNPh, or 2-pyrimidyl 2-Pym) electron acceptors are studied as their hexafluorophosphate salts. The intramolecular charge-transfer (ICT) energies (E-max) of these compounds decrease within each of the series in the order R = Me > Ph > 2,4-DNPh > 2-Pym, as the electron-accepting ability of the pyridinium ring increases. Hyper-Rayleigh scattering with femtosecond 1300 or 800 nm lasers yields fluorescence-free first hyperpolarizabilities ?, and static first hyperpolarizabilities ?(0)[H] are obtained via the two-state model. Dipole moment changes ??(12) for the ICT transitions obtained from Stark spectroscopy afford ?(0)[S] values by using ?(0) = 3??(12)(?(12))(2)/2 (E-max)(2) (?(12) = transition dipole moment). The ?(0)[S] data show that the combination of pyridyl N-arylation with conjugation extension affords large increases in ?(0). The ?(0)[H] data generally agree with this conclusion, but resonance effects may explain some apparent anomalies. X-ray structural studies on various salts reveal that the use of tosylate anions is not a generally applicable approach to engineering noncentrosymmetric structures of pyridinium salts. However, trans-N-phenyl-4-(4-dimethylaminophenyl-4-buta-1,3-dienyl)pyridinium hexafluorophosphate adopts the polar space group Cc, and shows a very large powder second harmonic generation efficiency from a 1907 nm laser; which is similar to that of the well-studied material trans-4'-(dimethylamino)-N-methyl-4-stilbazolium tosylate (DAST).

Quadratic Optical Nonlinearities of N‐Methyl and N‐Aryl Pyridinium Salts

Carbonylrhenium bromide complexes with conjugated pyridines fac-Br(OC)3ReL2 (L = FcCH:CH-p-C5H4N (Fc = ferrocenyl), FcCH:CHC(Me):CHCH:CHCH:C(Me)CH:CH-p-C5H4N, 1,1'Fc(CH:CH-p-C5H4N)2 p-Me2NC6H4CH:CHCH:CH-p-C5H4N (I), and p-Me2NC6H4CH:CHC(Me):CHCH:CHCH:C(Me)CH:CH-p-C5H4N) and cis-Br(OC)4ReL (L = FcCH:CH-p-C5H4N (II) and p-Me2NC6H4CH:CHCH:CH-p-C5H4N) were synthesized. The structures of I (monoclinic, C2/c, a = 18.3826(1), b = 15.1048(1), c = 28.5866(1) .ANG., b = 92.848(1) Deg, V = 7927.71(7) .ANG.3, Z = 8, rc = 1.636 g/cm3, m(MoKa) = 4.317 mm-1, F(000) = 3848, 7804 independent reflections, 480 refined parameters, R1 = 0.0726, wR2 = 0.1723) and II (rhombohedral, R.hivin.3, a = 30.357(4), c = 12.398(2) .ANG., V = 9895(2) .ANG.3, Z = 18, rc = 2.016 g/cm3, m(MoKa) = 8.003 mm-1, F(000) = 5688, 2930 independent reflections, 262 refined parameters, R1 = 0.0578, wR2 = 0.1048) were detd. by x-ray diffraction anal. Compd. I exhibits a remarkable quadratic hyperpolarizability. [on SciFinder (R)]

Synthesis and nonlinear optical properties of carbonylrhenium bromide complexes with conjugated pyridines

Hydrocarbon bridged metal complexes, XLIV. Donor–acceptor substituted Schiff bases of polyenes with transition metals2

Hydrocarbon bridged metal complexes

Schiff bases 111 were synthesized from α-amino acids or o-aminophenol and crocetindialdehyde, 2,7-dimethyloctatrienedial, terephthalaldehyde, or β,β′ -p-phenylendiacroleine The reactions of these Schiff bases with chloro-bridged complexes [(R3P)(Cl)M(η-Cl)]2 (M = Pd, Pt) and [(C5Me5)(Cl)Ir(°Cl)]2 gave the dinuclear complexes 12–31

Hydrocarbon‐Bridged Complexes, XL. Polyene‐Bridged Iridium(III), Palladium(II), and Platinum(II) Complexes of Schiff Bases from α,ω‐Polyene Dialdehydes and α‐Amino Acids or o‐Aminophenol

Oliver Briel

Papers

Synthesis and nonlinear optical properties of carbonylrhenium bromide complexes with conjugated pyridines

Hydrocarbon bridged metal complexes, XLIV. Donor–acceptor substituted Schiff bases of polyenes with transition metals2

Hydrocarbon bridged metal complexes

Hydrocarbon‐Bridged Complexes, XL. Polyene‐Bridged Iridium(III), Palladium(II), and Platinum(II) Complexes of Schiff Bases from α,ω‐Polyene Dialdehydes and α‐Amino Acids or o‐Aminophenol