Materials chemistry and the pursuit of new compounds through exploratory synthesis are having a strong impact in many technological fields. The field of nonlinear optics is directly impacted by the availability of enabling materials with high performance. Nonlinear optical (NLO) phenomena such as second harmonic and difference frequency generation (SHG and DFG, respectively) are effective at producing a coherent laser beam in difficult to reach frequency regions of the electromagnetic spectrum. Such regions include the infrared (IR), far-infrared, and terahertz frequencies. High performance NLO crystals are critical for applications utilizing these coherent light sources, and new materials are continuously sought for better conversion efficiency and performance. The class of metal chalcogenides is the most promising source of potential NLO materials with desirable properties particularly in the IR region where most classes of materials face various fundamental challenges. We review the recent developments...

Metal Chalcogenides: A Rich Source of Nonlinear Optical Materials

One-dimensional coordination polymers: applications to material science

The conditions required to produce zeolites with low framework density and extra-large pores are discussed. Correlations between framework stability and geometrical and topological descriptors are presented. An attempt has been made to rationalize the synthesis of extra-large-pore zeolites in terms of the synthesis mechanism, the directing effect of the organic structure directing agent (OSDA), the framework atoms, and the gel concentration. Extra-large-pore zeolites, including the recently discovered chiral mesoporous ITQ-37, are described and their catalytic and adsorption properties discussed. Finally, strategies are presented for the preparation of extra-large-pore zeolites with different pore topologies that can fulfill pre-established catalytic and adsorption targets.

Extra‐Large‐Pore Zeolites: Bridging the Gap between Micro and Mesoporous Structures

The development of nonlinear optical (NLO) borate crystals for generation of visible and UV light is reviewed. We first discussed on the basic principles of laser frequency conversion. Then, we examine the trends in research on NLO crystals. The background and present status of NLO borate crystals are summarized. The main considerations are focused on the discussion of crystals like CsLiB6O10 (CLBO), GdxY1−xCa4O(BO3)3 (GdYCOB) and K2Al2B2O7 (KAB). Properties of related materials like β-BaB2O2 (BBO), LiB3O5 (LBO), KBe2BO3F2 (KBBF), Sr2Be2BO7 (SBBO), CsB3O5 (CBO), GdCa4O(BO3)3 (GdCOB) and YCa4O(BO3)3 (YCOB) are included for comparison. We aim to provide a complete view of developing a new NLO borate material for actual laser applications. This review covers various aspects including the search for new materials, the growth of bulk crystals, the characterization of crystal properties as well as the development of new techniques to overcome obstacles in actual laser application, namely, thermal dephasing and laser-induced damage. Finally, perspectives on NLO borate crystals and all-solid-state UV lasers are evaluated.

Recent development of nonlinear optical borate crystals: key materials for generation of visible and UV light

Inorganic framework solids are no longer limited to just the silicates and phosphates. Recent research has revealed that carboxylates, arsenates, sulfates, selenates, selenites, germanates, phosphites can also form such structures. One of the emerging areas combines the rich coordination chemistry of the central metal ions of many of these structures with the flexibility and functionality of the organic linkers to give rise to organic-inorganic hybrid compounds. The compounds of the transition-metals appear to provide many variations arising from their coordination preferences, ligand geometry, and the valence state. In addition, the combination of the magnetic nature of the transition metal center with the channel structure of open frameworks suggests interesting potential applications. In this Review the synthesis, structures and properties of the various transition-metal open-framework compounds are discussed.

Open-framework structures of transition-metal compounds.

The potassium titanyl phosphate structure field: a model for new nonlinear optical materials

The solution-mediated synthesis and single crystal structure of (CN3H6)2·Zn(HPO3)2 are reported. This phase is built up from a three-dimensional framework of vertex-linked ZnO4 and HPO3 building units encapsulating the extra-framework guanidinium cations. The structure is stabilised by template-to-framework hydrogen bonding. The inorganic framework contains polyhedral 12-rings and shows a surprising similarity to those of some known organically-templated zinc phosphates.

(CN3H6)2·Zn(HPO3)2: An open-framework zincophosphite built up from polyhedral 12-rings

Electronic effects of substitution chemistry in the potassium titanyl phosphate (KTiOPO4) structure field: structure and optical properties of potassium vanadyl phosphate

Mark L. F. Phillips

Papers

The potassium titanyl phosphate structure field: a model for new nonlinear optical materials

(CN3H6)2·Zn(HPO3)2: An open-framework zincophosphite built up from polyhedral 12-rings

Electronic effects of substitution chemistry in the potassium titanyl phosphate (KTiOPO4) structure field: structure and optical properties of potassium vanadyl phosphate

Effects of substitution chemistry in the potassium titanyl phosphate (KTiOPO4) structure field

(CN4H7)2·Zn3(HPO3)4, a three-dimensional framework zincophosphite: an example of template–template co-operation?