Associations of organic and inorganic molecules involving non covalent and covalent interactions participate to a wide range of structures found in nature. Bridged silsesquioxanes (BS) can be designed with organic units selected to drive self-organization into a solid network. Therefore new hybrids functional materials with controlled morphologies can be synthesized. In particular urea groups, thanks to their ability to self-assemble though H bonds, have been incorporated in BS within the organic subunits (figure 1, UU). Depending on kinetics of the sol gel reaction, hybrid materials bridged by urea groups exhibiting a variety of textures and morphologies were synthetized. Considering the bridging group as a key element for the control of the assembly formed hybrids materials where thiourea groups have also been synthesized (Figure 1, UU or TT). As a matter of fact thiourea groups are also known to link them self via H bonds, but with geometry and strengths that can differ from urea links. Vibrational spectroscopy is used here to explore the self-organization mechanisms involved in the formation of urea bridged and thiourea bridged silsequioxanes. The influence of H-bonding strength and the self-organization properties of the urea and thiourea bridged organic substructures are explored through infra-red spectroscopy coupled with DFT calculations. Some particular vibrations such as amides and thio-amides vibrations are often considered as signatures of H bond strength. The thermal dependence dynamics of such signatures is studied as an indicator of the bond properties. Finally, in-situ high pressure vibrational measurements demonstrate the role of supramolecular interactions on the mechanical response of hybrid materials to high pressure.

In these lectures we present some results concerning the theoretical study of light waves [1-3] and of atomic matter waves [4-6] propagating in artificial atomic crystals realized by atoms trapped at the notes of an optical lattice and forming 2D or 3D (Bravais or non-Bravais) crystals. The case of not perfectly filled lattices will be also considered to study of the absence of transport due to the occurrence of the Anderson localization in disordered systems. ---------- [1] Fano-Hopfield model and photonic band gaps for an arbitrary atomic lattice Mauro Antezza, Yvan Castin Phys. Rev. A 80, 013816 (2009) [2] Spectrum of light in a quantum fluctuating periodic structure Mauro Antezza, Yvan Castin Phys. Rev. Lett. 103, 123903 (2009) [3] Photonic band gap in an imperfect atomic diamond lattice: penetration depth and effects of finite size and vacancies Mauro Antezza, Yvan Castin Phys. Rev. A 88, 033844 (2013) [4] Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers Mauro Antezza, Yvan Castin, David A. W. Hutchinson Phys. Rev. A 82, 043602 (2010) [5] Matter waves in atomic artificial graphene Nicola Bartolo, and Mauro Antezza Europhys. Lett. 107, 30006 (2014) [6] Matter waves in two-dimensional arbitrary atomic crystals Nicola Bartolo, and Mauro Antezza Phys. Rev. A 90, 033617 (2014)

High-pressure polarized Raman spectra of vitreous silica are measured up to 8 GPa in a diamond-anvil cell at room temperature. The combined use of either a nonpenetrating pressurizing medium—argon—or a penetrating one—helium, allows one to separate density from stress effects on the Raman frequencies. In the framework of a simple central force model, the results emphasize the distinct role played by the shrinkage of the intertetrahedral angle Si-O-Si and the force-constant stiffening during the compression. The polarization analysis further reveals the existence of an additional isotropic component in the high-frequency wing of the boson peak. The pressure dependence of the genuine boson peak frequency is found to be much weaker than previously reported and even goes through a minimum around 2 GPa in remarkable coincidence with the anomalous compressibility maximum of silica.