Tunable Engineered Extracellular Matrix Materials: Polyelectrolyte Multilayers Promote Improved Neural Cell Growth and Survival.

Poly-d-lysine (PDL) and poly-l-lysine are standard surfaces for culturing neural cells; however, both are relatively unstable, costly, and the coated surface typically must be prepared immediately before use. Here, polyelectrolyte multilayers (PEMs) are employed as highly stable, relatively inexpensive, alternative substrates to support primary neural cell culture. Initial findings identify specific silk-based PEMs that significantly outperform the capacity of PDL to promote neuronal survival and process extension.

Quadratic and Cubic Optical Nonlinearities of Y-Shaped and Distorted-H-Shaped Arylalkynylruthenium Complexes.

Straightforward syntheses of bis[bis{1,2-bis(diphenylphosphino)ethane}ruthenium]-functionalized 1,3,5-triethynylbenzene-cored complexes via a methodology employing "steric control" permit facile formation of Y-shaped Sonogashira coupling products and distorted-H-shaped homo-coupled quadrupolar products. Cyclic voltammetric data from these products reveal two reversible metal alkynyl-localized oxidation processes for all complexes. The wavelengths of the linear optical absorption maxima are dominated by the nature of the peripheral alkynyl ligand rather than the substituent at the unique arm of the "Y" or at the quadrupolar complex "core".

Divergent synthesis of ruthenium alkynyl dendrimers and a two-photon absorption cross-section dendritic effect.

Ruthenium alkynyl dendrimers up to second generation in size have been prepared by a divergent route and exploiting Sonogashira coupling. The cubic NLO properties have been examined by wide spectral range fs Z-scan studies, revealing an NLO dendritic effect. The significant increase in NLO properties seen on generation increase is maintained when the coefficients are scaled by the number of metal atoms, the dendrimer molecular weights, or the number of "effective" (delocalizable π) electrons in the dendritic structures.

Organometallic complexes for nonlinear optics, 47 - synthesis and cubic optical nonlinearity of a stilbenylethynylruthenium dendrimer.

The synthesis of the 1st generation dendrimer 1,3,5-{trans-[Ru(C≡C-3,5-(trans-[Ru(C≡CPh)(dppe)(2) (C≡CC(6) H(4) -4-(E)-CHCH)])(2) C(6) H(3) )(dppe)(2) (C≡CC(6) H(4) -4-(E)-CHCH)]}(3) C(6) H(3) proceeds by a novel route that features Emmons-Horner-Wadsworth coupling of 1,3,5-C(6) H(3) (CH(2) PO(OEt)(2) )(3) with trans-[Ru(C≡CC(6) H(4) -4-CHO)Cl(dppe)(2) ] and 1-I-C(6) H(3) -3,5-(CH(2) PO(OEt)(2) )(2) with trans-[Ru(C≡CPh)(C≡CC(6) H(4) -4-CHO)(dppe)(2) ] as key steps. The stilbenylethynylruthenium dendrimer is much more soluble than its ethynylated analog 1,3,5-{trans-[Ru(C≡C-3,5-(trans-[Ru(C≡CPh)(dppe)(2) (C≡CC(6) H(4) -4-C≡C)])(2) C(6) H(3) )(dppe)(2) (C≡CC(6) H(4) -4-C≡C)]}(3) C(6) H(3) and, in contrast to the ethynylated analog, is a two-photon absorber at telecommunications wavelengths.

Electron-rich iron/ruthenium arylalkynyl complexes for third-order nonlinear optics: redox-switching between three states.

The new [(η(2)-dppe)(η(5)-C(5)Me(5))Fe(C≡C-1,4-C(6)H(4)C≡C)Ru(η(2) -dppe)(2) C≡C(C(6)H(5))] complex (3-H) and its hexanuclear relative [{(η(2)-dppe)(η(5)-C(5) Me(5))Fe(C≡C-1,4-C(6)H(4)-C≡C)Ru(η(2)-dppe)(2)(C≡C-1,4-C(6)H(4)C≡C)(3)(1,3,5-C(6)H(3))] (4) have been synthesized and characterized. The linear and cubic nonlinear optical properties of these compounds in their various redox states have been studied along with those of the analogous complexes [(η(2)-dppe)(η(5)-C(5)Me(5))Fe(C≡C-1,4-C(6)H(4)C≡C)Ru(η(2)-dppe)(2)R][PF(6)](n) (n=0-2; R=Cl, 2-Cl; R=C≡C(4-C(6)H(4)NO(2)),3-NO(2)). We show that molecules exhibiting large third-order nonlinearities can be obtained by assembling such dinuclear Fe/Ru units around a central 1,3,5-substituted C(6)H(3) core.