Yeda Research and Develpment & Co. Ltd

Yeda Research and Development Co. Ltd. at the Weizmann Institute of

Valeri A Krongauz

Shlomo Yitzchaik

Schlomo Yitzchaik

Frida Buchhultz

Alexander Zelichenok

Garry Berkovic

Alexandre Chif

Judith Ratner

Emmanuel Lurie

Vladimir Tchernoivanov

Frida Buchholz

Alexander Zelichonok

Alexander Aizikovich

Felix P Shvartsman

A photochromic compound for incorporation into plastic articles, particularly into a plastic lens, is selected from a spiro(indoline)naphtho(2,1-b)(1,4)oxazine and a spiro(indoline)naphtho(1,2-b)(1,4)oxazine containing a group selected from: (a) &#x2014;CH2&#x2014;CnF2n+1 at the nitrogen atom in the 1-position on the indoline part of the molecule, wherein n is an integer of 1 to 6; (b) &#x2014;COOR at the 3-position on the indoline part of the molecule, wherein R is (i) C1-C6 alkyl optionally substituted by fluoro, C1-C4 alkoxy or fluoroalkoxy, C1-C4 alkylcarbonyloxy, C2-C4 alkenylcarbonyloxy, C3-C6 cycloalkyl or aryl; (ii) C2-C6 alkenyl with a terminal double bond; (iii) C3-C6 cycloalkyl optionally substituted by fluoro; or (iv) aryl; (c) an &#x2014;OCF3 group on the benzene ring of the indoline part of the molecule; (d) an aryl(dialkyl)methyl group of the formula &#x2014;C(aryl)(CnH2n+1)(CmH2m+1), wherein n and m are integers from 1 to 5, linked to one of the benzene rings of the naphthoxazine part of the molecule; and (e) any combination of (a), (b), (c) and/or (d).

Photochromic spiro(indoline)naphthoxazines

A photochromic naphthopyran of formula (I) wherein R through R , which may be the same or different, are independently selected from the group consisting of hydrogen, C -C alkyl, C -C alkoxy, halogen, C -C alkylcarbonyloxy, benzoyloxy, C -C cycloalkyl, phenyl, and NR R , wherein R and R are each C -C alkyl or together with the N atom form a 5-12 membered monocyclic or polycyclic ring having, optionally, one or more further heteroatoms; R is hydrogen, alkyl or alkoxy; and >C(C H ) (C H ) is a tert-alkylene grup, wherein n and m are integers from 1 to 5.

Photochromic naphthopyran compounds

Polysiloxane copolymers containing both photochromic and lightstabilizing groups with enhanced UV-fatigue resistance can be used as coatings for devices with variable optical density, including lenses, glazing, textiles and the like, to provide light-sensitive darkening effects. The photochromic groups are spironaphtooxazine groups and the lightstabilizing groups are hindered amine light stabilizing (HALS) groups.

Photochromic spirooxazine polysiloxanes

A method of making a photochromic polysiloxane includes the steps of forming a photochromic spironaphthooxazine monomer including an alkene terminated side and, by addition reaction, covalently bonding the alkene carbon to [SiH] moieties of a siloxane polymer. Novel spironaphthooxazine monomers and photochromic polysiloxanes are disclosed.

Photochromic spirooxazine monomers and polysiloxanes

Method for the generation of second order nonlinear optical effects, including second harmonic generation, which comprises the steps of: i preparing a material in an xy planar film or xyz tridimensional form on a substrate and placing parallel electrodes on top of, inside, above or below said material, such that there is no protrusion of said electrodes into said material or a protrusion of at least one of said electrodes into said material is thinner than said material, wherein said material comprises at least one species of a hyperpolarizable component (a) and at least one species of a glass-forming organic material (b) providing a non-crystalline solid matrix in which molecules are not mobile, said components (a) and (b) being either distinct species or portions of a bifunctional molecule; ii subjecting said material of step (i) to an electric field essentially along the x-axis thereof; and iii directing a beam of light to impinge on and to be transmitted through said material treated as in step (ii), thus generating second order nonlinear optical effects which are characterized by one or more X.sup.(2) components whose indices are zzz, zxx, zyy and permutations thereof.

Method and system for producing second order nonlinear optical effects

In a system and method for generating second order nonlinear optical effects and in particular second order harmonic radiation (SHG), a beam of light is transmitted through and/or reflected from a substance which includes both at least one species selected from amorphous and glassy organic materials and at least one species of hyperpolarizable component, and which is in xy planar film or coating form or in light-transmissive 3-dimensional form and which substance is preferably subjected to a polarizing electric field, such that (a) when the substance is in the form of an xy planar film or coating, the field is applied in the plane of the film and the beam of light is caused to impinge thereon at angle other than normal to the xy plane, (b) when the substance is in 3-dimensional form, the field is applied along a line (an arbitrary x-axis) and the beam of light includes components polarized along at least one of the y- and z-axes; and (c) emergent SHG, which includes at least one component which is polarized perpendicular to the direction of polarization induced by the electric field in the hyperpolarizable component(s), is detected, observed, measured and/or utilized.

There are provided compounds which give quasi-liquid crystals, which comprise a mesogenic group, which can contain bridging groups, a bridging group and a spiropyran moiety having a 2H pyran ring, a terminal group being attached to the mesogenic group. The mesogenic group contains two aromatic, heterocyclic or cycloaliphatic ring structures. The compounds are prepared by a coupling reaction of mesogenic groups with a spiropyran compound via a suitable bridging group. There is provided a process for producing quasi-liquid crystalline (QLC) films which are useful for producing a wide variety of devices based on the optical non-linearity of generation of second harmonics by such films. Such devices can also be based on ferroelectric, pyroelectric, piezoelectric effects and photoactivity of such oriented QLC films.

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Rehovot, Israel

Valeri A Krongauz