A novel second-order non-linear optical coordination polymer with three-fold interpenetrated CdSO4-type network constructed by carboxylate–sulfonate ligands and strontium ions

A nonlinear optical cadmium(ii)-based metal–organic framework with chiral helical chains derived from an achiral bent dicarboxylate ligand

The design of a nonlinear optical (NLO) MOF material from an achiral bent dicarboxylate ligand is presented.

Synthesis, crystal structure and topological analysis of a three-dimensional polymeric network based on zinc(II), potassium and 5-sulfobenzene-1,3-dicarboxylate (SIP)

Aromatic polycarboxylate linkers provide structural rigidity and strong interactions among the metal centre and the carboxylate O atoms. A new three-dimensional coordination polymer namely, catena-poly[potassium [tetraaqua(μ-5-sulfobenzene-1,3-dicarboxylato)zinc(II)]], {K[Zn(C₈H₃O₇S)(H₂O)₄]}_n or {K[Zn(SIP)(H₂O)₄]}_n, where SIP is 5-sulfobenzene-1,3-dicarboxylate or 5-sulfoisophthalate, was obtained and characterized by elemental analysis and IR vibrational spectroscopy, and the single-crystal structure was determined by X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P2₁/n with Z = 4. Topological analysis revealed that K-O interactions form a two-dimensional network, which is uninodal 4-connected and can be described with a point symbol (4⁴.6²), and this plane network is classified as sql/Shubnikov. The layers are connected by Zn²⁺ ions coordinated to the SIP linker, forming a three-dimensional network. This net is a trinodal (3,5,6)-connected system with point symbol (3.4⁴.5².6².7³.8³).(3.4⁴.5².6².7).(3.7²).

Metal-organic frameworks as competitive materials for non-linear optics

The last five years have witnessed a huge breakthrough in the creation and the study of the properties of a new class of compounds - metamaterials. The next stage of this technological revolution will be the development of active, controllable, and non-linear metamaterials, surpassing natural media as platforms for optical data processing and quantum information applications. However, scientists are constantly faced with the need to find new methods that can ensure the formation of quantum and non-linear metamaterials with higher resolution. One such method of producing metamaterials in the future, which will provide scalability and availability, is chemical synthesis. Meanwhile, the chemical synthesis of organized 3D structures with a period of a few nanometers and a size of up to a few millimeters is not an easy task and is yet to be resolved. The most promising avenue seems to be the use of highly porous structures based on metal-organic frameworks that have demonstrated their unique properties in the field of non-linear optics (NLO) over the past three years. Thus, the aim of this review is to examine current progress and the possibilities of using metal-organic frameworks in the field of non-linear optics as chemically obtained metamaterials of the future. The review begins by presenting the theoretical principles of physical phenomena represented by mathematical descriptions for clarity. Major attention is paid to the second harmonic generation (SHG) effect. In this section we compare inorganic single crystals, which are most commonly used to study the effect in question, to organic materials, which also possess the required properties. Based on these data, we present a rationale for the possibility of studying the non-linear optical properties of metal-organic structures as well as describing the use of synthetic approaches and the difficulties associated with them. The second part of the review explicitly acquaints the reader with a new class of materials which successfully combines the positive properties of organic and inorganic materials. Using recently synthesized metal-organic frameworks and coordination polymers in the field of non-linear optics as an example, we consider synthetic approaches used for obtaining materials with desired properties and the factors to be considered in this case. Finally, probable trends towards improving the quality of the synthesized materials with regards to their further use in the field of non-linear optical effects are described.

Control of chirality and catenation in cobalt and cadmium camphorate coordination complexes

Five cobalt or cadmium camphorate coordination polymers with various flexible-tether dipyridylamide ligands were structurally characterized. {[Co₂(d-cam)₂(pdn)]·2H₂O}_n (3, pdn = N,N′-(propane-1,3-diyl)dinicotinamide) has a self-penetrated 4⁴6⁸10 mab network. {[Cd₂(d-cam)₂(pdn)]·H₂O}_n (4) shows a new 3,7-connected 3D network. The cadmium complexes were assayed for luminescent and nitrobenzene detection properties.

Nitroaromatic-detecting cadmium cyclohexyldicarboxylate coordination polymers with bis(4-pyridylmethyl)piperazine coligands and unprecedented 2D and 3D topologies

Hydrothermal reaction of cadmium nitrate, bis(4-pyridylmethyl)piperazine (4-bpmp), and a variety of cyclohexyldicarboxylate ligands generated three new coordination polymer solids that were structurally characterized via single-crystal X-ray diffraction.