Richard Robson

Bio: Richard Robson is an academic researcher from University of Melbourne. The author has contributed to research in topics: Crystal structure & Coordination polymer. The author has an hindex of 50, co-authored 172 publications receiving 14962 citations. Previous affiliations of Richard Robson include Deakin University & Monash University, Clayton campus.

Interpenetrating Nets: Ordered, Periodic Entanglement.

Abstract: Independent one-, two-, and even three-dimensional nets interpenetrate each other in many solid-state structures of polymeric, hydrogen-bonded nets and coordination polymers. For example, the interpenetration of the adamantane units of two diamondlike nets is shown on the right. A detailed and systematic examination of many interpenetrating nets of this kind is made, and implications for crystal engineering are discussed.

Assembly of porphyrin building blocks into network structures with large channels

Abstract: CRYSTAL engineering—the deliberate design and construction of crystal structures from molecular components—promises to provide solid-state materials with specific and useful chemical, mechanical, electronic or optical properties1. In most of the molecular crystals considered so far, van der Waals forces and hydrogen bonding govern the crystal packing2–7. Zeolites, pillared clays and related microporous materials, which have been studied extensively because their porous structures convey useful catalytic activity8,9, can now also be 'engineered' to some extent10,11. We are exploring ways12–14 to construct channelled solids with very different chemical architectures and potentially different catalytic activity from those of zeolites. Here we show that porphyrin building blocks can be used to construct three-dimensional networks with the topology of the PtS structure, containing large channels. In our materials the channels are filled with solvent molecules, and crystalline order is lost on solvent removal. Nevertheless, the results show that it is possible to use simple molecular building blocks to engineer specific frameworks which, if they can be made robust, may offer new catalytic potential.

A net-based approach to coordination polymers

Abstract: True crystal engineering of coordination polymers with useful structure-based properties by design remains a distant prospect. The exploratory, experimental net-based approach to the construction of coordination polymers described in this article has provided a few examples of structures obtained by design, but also serendipitously revealed numbers of unprecedented and interesting structures that were totally unexpected. Further work with coordination polymers can confidently be expected to provide many similar surprises. It is proposed that carefully designed connecting ligands capable of binding metal centres strongly and predictably at chelating sites may afford improved structural control in network assembly and more robust network structures.

Reticular synthesis and the design of new materials

Abstract: The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.

Selective gas adsorption and separation in metal–organic frameworks

Abstract: Adsorptive separation is very important in industry. Generally, the process uses porous solid materials such as zeolites, activated carbons, or silica gels as adsorbents. With an ever increasing need for a more efficient, energy-saving, and environmentally benign procedure for gas separation, adsorbents with tailored structures and tunable surface properties must be found. Metal–organic frameworks (MOFs), constructed by metal-containing nodes connected by organic bridges, are such a new type of porous materials. They are promising candidates as adsorbents for gas separations due to their large surface areas, adjustable pore sizes and controllable properties, as well as acceptable thermal stability. This critical review starts with a brief introduction to gas separation and purification based on selective adsorption, followed by a review of gas selective adsorption in rigid and flexible MOFs. Based on possible mechanisms, selective adsorptions observed in MOFs are classified, and primary relationships between adsorption properties and framework features are analyzed. As a specific example of tailor-made MOFs, mesh-adjustable molecular sieves are emphasized and the underlying working mechanism elucidated. In addition to the experimental aspect, theoretical investigations from adsorption equilibrium to diffusion dynamics via molecular simulations are also briefly reviewed. Furthermore, gas separations in MOFs, including the molecular sieving effect, kinetic separation, the quantum sieving effect for H2/D2 separation, and MOF-based membranes are also summarized (227 references).

Metal–organic framework materials as catalysts

Abstract: A critical review of the emerging field of MOF-based catalysis is presented. Discussed are examples of: (a) opportunistic catalysis with metal nodes, (b) designed catalysis with framework nodes, (c) catalysis by homogeneous catalysts incorporated as framework struts, (d) catalysis by MOF-encapsulated molecular species, (e) catalysis by metal-free organic struts or cavity modifiers, and (f) catalysis by MOF-encapsulated clusters (66 references).

Design and synthesis of an exceptionally stable and highly porous metal-organic framework

Abstract: Open metal–organic frameworks are widely regarded as promising materials for applications1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 in catalysis, separation, gas storage and molecular recognition. Compared to conventionally used microporous inorganic materials such as zeolites, these organic structures have the potential for more flexible rational design, through control of the architecture and functionalization of the pores. So far, the inability of these open frameworks to support permanent porosity and to avoid collapsing in the absence of guest molecules, such as solvents, has hindered further progress in the field14,15. Here we report the synthesis of a metal–organic framework which remains crystalline, as evidenced by X-ray single-crystal analyses, and stable when fully desolvated and when heated up to 300?°C. This synthesis is achieved by borrowing ideas from metal carboxylate cluster chemistry, where an organic dicarboxylate linker is used in a reaction that gives supertetrahedron clusters when capped with monocarboxylates. The rigid and divergent character of the added linker allows the articulation of the clusters into a three-dimensional framework resulting in a structure with higher apparent surface area and pore volume than most porous crystalline zeolites. This simple and potentially universal design strategy is currently being pursued in the synthesis of new phases and composites, and for gas-storage applications.