[show abstract][hide abstract] ABSTRACT: The development of new photonic materials is a key step toward improvement of existing optical devices and for the preparation of a new generation of systems. Therefore synthesis of photonic hybrid materials with a thorough understanding and control of the microstructure-to-properties relationships is crucial. In this perspective, a new preparation method based on fast gelation reactions using simple dispersion of dyes without strong covalent bonding between dye and matrix has been developed. This new sol-gel method is demonstrated through synthesis of monolithic siloxane-based hybrid materials highly doped by various platinum(II) acetylide derivatives. Concentrations of the chromophores as high as 400 mM were obtained and resulted in unprecedented optical power limiting (OPL) performance at 532 nm of the surface-polished solids. Static and time-resolved photoluminescence of the prepared hybrid materials were consistent with both OPL data and previous studies of similar Pt(II) compounds in solution. The impacts of the microstructure and the chemical composition of the matrix on the spectroscopic properties, are discussed.
[show abstract][hide abstract] ABSTRACT: We have recently reported a new class of macrocycle, the thiacalixthianthrenes. This paper describes some attempts to modify thiacalixthianthrene and a study of the structure of oxidized derivatives.
[show abstract][hide abstract] ABSTRACT: The Letter is dedicated to the memory of Dr. J. M. Létoffé and Dr. B. Bonnetot Abstract—New thianthrene based macrocycles with basket shaped structures were prepared by thermal treatment of tetrakis-(N,N 0 -dimethylthiocarbamoyl)-tetra-tert-butyl-thiacalixarene. Their structural characterization as well as the study of the formation mechanisms are presented in this article. The influence of the conformation of the starting thiacalixarene on the reaction is also discussed.
[show abstract][hide abstract] ABSTRACT: p-Tetrakis(phenylazo)-tetra-hydroxythiacalixarene shows complexing properties with neutral molecules. A complex with pyridine was crystallized and the crystal structure determined. The crystals are monoclinic, space group C2/c, a = 49.953(10), b = 21.566(4), c = 23.448(5) Å, ß = 105.12(3)°, V = 24386(8) Å 3, Z = 16. Two macrocycles are positioned in such a way that they form a cavity where two pyridine molecules are encapsulated giving a 2:2 endocomplex. 5.5 other pyridine molecules are trapped between the macrocycles, two of them giving H-bonds with the calixarenes.
Journal of Inclusion Phenomena 01/2003; 46(1):15-17. · 1.40 Impact Factor
[show abstract][hide abstract] ABSTRACT: Macrocyclic thiacalixarenes have interesting non-linear optical properties. Thiacalixarenes bearing phenylazo, imino, ethynylic groups or platinum derived acetylides on the upper rims were designed, prepared and fully characterised. They showed interesting properties for optical limiting. Moreover these macrocycles are highly soluble in organic solvents and can easily be embedded in inorganic matrix using the sol-gel routes. Thiacalixarene based class I and II solid-state materials were prepared and their optical limiting behaviour was investigated.
Materials Research Society symposia proceedings. Materials Research Society 01/2003; 771:L.7.16.1.
[show abstract][hide abstract] ABSTRACT: The chemistry of the family of thiacalixarenes remains poorly documented although the potentiality of these molecules for complexing reactions or optical applications has been demonstrated. The reaction and the mechanism of the nitration of tetrahydroxythiacalixarene are reported in this paper. The synthesis and structural characterization of 5,11,17,23-tetranitro-25,26,27,28-tetrahydroxythiacalixarene, as well as its reduction to tetraaminotetrahydroxythiacalixarene and the formation of tetra(4-pyridylimino)tetrahydroxythiacalixarene are discussed in this article.
New Journal of Chemistry 01/2002; 26(5):651-655. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: p-Tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalixarene and p-tetrakis(phenylazo)tetrahydroxytetrathiacalixarene were prepared and fully characterized using 1H and 13C NMR, mass spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The solid-state structure of p-tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalixarene was investigated by single crystal X-ray diffraction. It crystallized in the triclinic system (space group: P). z-Scan experiments were performed on the p-tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalixarene showing non linear absorption due to two photon absorption with a TPA cross-section of about 50 × 10−50 cm4 s per photon. Optical power limiting measurements on the p-tetrakis(phenylazo)tetrahydroxytetrathiacalixarene
at 532 nm (48% linear transmission) was found to limit the energy to 9 µJ.
Journal of Materials Chemistry 01/2001; 11:3014. · 5.97 Impact Factor