Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter at the nanoscale. We do this by exploring ways to shape light and its environment. It's what we call active and passive control. Our current focus is on the interaction of light with biomolecules and nanostructures. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
We participate in the EU-COST actions MP1102: Coherent Raman microscopy (MicroCor) and CM1202: Supramolecular photocatalytic water splitting (PERSPECT-H2O)

 

CHIRAL PYRROLO[1,2-A]QUINOLINES AS 2ND-ORDER NONLINEAR OPTICAL- MATERIALS


KELDERMAN E, VERBOOM W, ENGBERSEN JFJ, HARKEMA S, HEESINK GJT, LEHMUSVAARA E, VANHULST NF, REINHOUDT DN, DERHAEG L, PERSOONS A
CHEMISTRY OF MATERIALS
vol 4 issue 3: p626-p631 MAY-JUN 1992

The synthesis and nonlinear optical properties of a series of chiral pyrrolo[1,2-a]quinolines la-e is presented. The microscopic hyperpolarizabilities (beta(z)) were determined by EFISH measurements and the macroscopic susceptibilities (X2) were estimated by the Kurtz powder test. A small fixed angle of the annelated pyrrolidine donor unit with respect to the aromatic-pi-system renders the whole donor-pi-acceptor system chiral. The small deviation from planarity of approximately 10 +/- 3-degrees causes no observable reduction of the microscopic beta(z) value in comparison with the planar conjugated N,N- dimethylaniline analogues. The powder test showed phase matching for all pyrrolo[1,2-a]quinolines with an electron- withdrawing substituent at C-7 (1b-e). The aldehyde 1b crystallizes in the P2(1)2(1)2(1) space group and was calculated to have an efficiency of 8.3% of beta under optimal phasematch conditions. The nitro derivative 1c crystallizes in the favorable space group P2(1) (Z = 2) in which the angles of the two independent molecules with the optical b axis are 71.7- degrees and 43.5-degrees.
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