Building-integrated sunlight harvesting utilizing laminated glass luminescent solar concentrators (LSCs) is proposed. By incorporating high quantum yield (>90%), NIR-emitting CuInS 2 /ZnS quantum dots into the polymer interlayer between two sheets of lowiron float glass, a record optical efficiency of 8.1% is demonstrated for a 10 cm × 10 cm device that transmits ∼44% visible light. After completing prototypes by attaching silicon solar cells along the perimeter of the device, the electrical power conversion efficiency was certified at 2.2% with a black background and at 2.9% using a reflective substrate. This "drop-in" LSC solution is particularly attractive because it fits within the existing glazing industry value chain with only modest changes to typical glazing products. Performance modeling predicts >1 GWh annual electricity production for a typical urban skyscraper in most major U.S. cities, enabling significant energy cost savings and potentially "netzero" buildings.

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~~~~ ~New chromenes annulated with different six-membered azaheterocycles were prepared, i.e., the 3H-pyrano[3,2-Aquinolines 9/10 and 14, the 8H-pyrano[2,3-h]isoquinoline 11, the XH-pyrano[3,2-f]quinazoline 12, the XH-pyrano[3,2-flquinoxaline 13, and the 2H-pyrano[2,3-flisoquinoline 15. The synthesis was achieved using conveniently substituted a$-unsaturated aldehydes and organotitanium intermediates arising from azaheterocyclic phenols. Their photochromic behaviour (photocolouration yield, UVjVIS spectrum of photomerocyanines, rate constant of thermal bleaching) were studied besides those of corresponding naphthopyrans. The heterocycle effect and the role of substituents in the pyran moiety were investigated quantitatively through the study of the photochromic properties and the solvent effects. Diaryl-substituted azino-fused chromenes, especially isoquinoline derivatives, exhibit increased colourabilities and bathochromically shifted spectra for photomerocyanines which open up new prospects for photochromic applications.

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Ab initio and semiempirical quantum mechanical calculations were performed to study the electronic spectra of spiroxazine photochromic compounds as well as the corresponding photoisomers. Ground-state geometries were optimized based on density functional theory (DFT). Excitation energies of the different forms were calculated using the time-dependent density functional theory (TD-DFT) method. Semiempirical calculations including configuration interactions were performed to detail the mechanism of ring opening in excited states. On the basis of the obtained potential energy profile, a complete mechanism of photocoloration able to clarify some experimental findings is provided. A correlation of the experimental quantum yield of photocoloration with the calculated properties as a function of substituent effects is proposed.

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Solvatochromic and Photochromic Characteristics of New 1,3-Di hydrospiro[2H-indole-2,2'-[ 2 H ] -bipyrido [3,2-fl[2,3-h] [I ,4] benzoxazines]