J. B. González-Díaz, J. M. García-Martín, A. García-Martín, D. Navas, A. Asenjo, M. Vázquez, M. Hernández-Vélez, and G. Armelles Instituto de Microelectrónica de Madrid (IMM-CNM-CSIC), Isaac Newton 8, Tres Cantos, 28760 Madrid, Spain Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain Department of Materials Science and Enginee...

We demonstrate a type of meta-atom for creating metamaterials with giant nonlinear optical activity but vanishing linear optical activity in a wide frequency range. Such properties are not found in any natural materials, and we call this regime as pure nonlinear optical activity. We further extend our design concept and show that the metamaterial can be tuned dynamically to exhibit either posit...

This study established a LabVIEW-based virtual instrument system to measure optical activity through the communication of conventional optical instrument with computer via RS232 port. This system realized the functions for automatic acquisition, real-time display, data processing, results playback, and so forth. Therefore, it improved accuracy of the measurement results by avoiding the artifici...

Cinerone [2-(2'-cis-butenyl)-3-methyl-2-cyclopenten-1-one] is hydroxylated to cinerolone [2-(2'-cis-butenyl)-3-methyl-4-hydroxy-2-cyclopenten-1-one] by a number of streptomycetes, bacteria, and fungi. Aspergillus niger ATCC 9,142 and Streptomyces aureofaciens ATCC 10,762 were found to be the most effective hydroxylators. The optical activity of the product was found to range from [alpha](D) (25...

We show that the unexpected chirality of aggregated structures based on an uncharged achiral porphyrin system originates from small temperature gradients that act as an asymmetrical physical perturbation; the consequent thermal force gives rise to the thermophoretic motion of the aggregates. We establish that the induced optical activity can be controlled, and even vanished, by minimizing the t...

We explore the influence of the phase of localized plasmon resonances on the magneto-optical activity of nanoferromagnets. We demonstrate that these systems can be described as two orthogonal damped oscillators coupled by the spin-orbit interaction. We prove that only the spin-orbit induced transverse plasmon plays an active role on the magneto-optical properties by controlling the relative amp...

The paper presents an application of the asymmetry approach to spirooxindoles via Brevicolline, Cinchonidine or Cinchonine catalyzed one-pot multicomponent synthesis. Brevicolline, in comparison with Cinchonidine or Cinchonine, catalyzes the reaction of isatins, acetylacetone/ethyl 3-oxobutanoate and malononitrile, with the formation of spiro[oxindole-3,4'-4'H-pirane] derivatives in an opticall...

A simple graphical method is proposed to distinguish between two-state and gradual alterations in DNA conformation from circular dichroic spectra. The method is advantageous particularly to identify two-state conformational isomerizations which exhibit low degree of cooperativity. The usefulness of the method is illustrated on the examples of two synthetic DNA molecules which isomerize due to t...

We observe that optical activity in light scattering can be probed using types of illuminating light other than single plane (or quasi plane) waves and that this introduces new possibilities for the study of molecules and atoms. We demonstrate this explicitly for natural Rayleigh optical activity which, we suggest, could be exploited as a new form of spectroscopy for chiral molecules through th...

The complete optical-gyration tensor for a monoclinic crystal of (2R, 3R)-(+)C4H6O6 has been determined by the tilter method at a wavelength of 680 nm. The tensor components in terms of rotatory power in relation to the principal axes of the indicatrix were found to be ρ◦ 11 = 79(7), ρ◦ 22 = 90(13), ρ◦ 33 = −70(4), ρ◦ 23 = −18(8)◦ mm−1 with ρ = −12.3(1.0)◦ mm−1 in the optic-axis directions. The...