Craig M. Robertson

Bio: Craig M. Robertson is an academic researcher from University of Liverpool. The author has contributed to research in topics: Catalysis & Crystal structure. The author has an hindex of 30, co-authored 75 publications receiving 2184 citations. Previous affiliations of Craig M. Robertson include Memorial University of Newfoundland & University of Louisville.

Two-Dimensional Structural Motif in Thienoacene Semiconductors: Synthesis, Structure, and Properties of Tetrathienoanthracene Isomers

Abstract: Stille coupling of 2- and 3-(tributylstannyl)thiophene derivatives with tetrabromobenzene followed by oxidative cyclization provides a simple, two-step synthetic route to two isomeric tetrathienoanthracene structures (13 and 14). The materials are characterized by a remarkable thermal stability, both in air (Tdec ≈ 400 °C) and under nitrogen (sublimed with no decomposition at 450–500 °C). Optical studies of the parent and alkylated compounds showed sky-blue photoluminescence with quantum yields ranging between 0.17 and 0.40 and Stokes shifts of 0.03–0.16 eV. Both the optical properties and electrochemical behavior depend strongly on the position of the heteroatoms. Structural studies with X-ray crystallography (for 3D single crystals) and scanning tunneling microscopy (for 2D monolayers) indicate a high level of order, with similar intermolecular interactions for both isomers. The alkylated materials 13b and 14b have been used to fabricate thin-film transistors by both vacuum evaporation and solution proc...

Enhanced conductivity and magnetic ordering in isostructural heavy atom radicals.

Abstract: Synthetic methods have been developed to generate the complete series of resonance-stabilized heterocyclic thia/selenazyl radicals 1a−4a. X-ray crystallographic studies confirm that all four radicals are isostructural, belonging to the tetragonal space group P421m. The crystal structures consist of slipped π-stack arrays of undimerized radicals packed about 4 centers running along the z direction, an arrangement which gives rise to a complex lattice-wide network of close intermolecular E2---E2′ contacts. Variable temperature conductivity (σ) measurements reveal an increase in conductivity with increasing selenium content, particularly so when selenium occupies the E2 position, with σ(300 K) reaching a maximum (for E1 = E2 = Se) of 3.0 × 10−4 S cm−1. Thermal activation energies Eact follow a similar profile, decreasing with increasing selenium content along the series 1a (0.43 eV), 3a (0.31 eV), 2a (0.27 eV), 4a (0.19 eV). Variable temperature magnetic susceptibility measurements indicate that all four r...

Primary amines by transfer hydrogenative reductive amination of ketones by using cyclometalated Ir(III) catalysts.

Abstract: Cyclometalated iridium complexes are found to be versatile catalysts for the direct reductive amination (DRA) of carbonyls to give primary amines under transfer-hydrogenation conditions with ammonium formate as both the nitrogen and hydrogen source. These complexes are easy to synthesise and their ligands can be easily tuned. The activity and chemoselectivity of the catalyst towards primary amines is excellent, with a substrate to catalyst ratio (S/C) of 1000 being feasible. Both aromatic and aliphatic primary amines were obtained in high yields. Moreover, a first example of homogeneously catalysed transfer-hydrogenative DRA has been realised for β-keto ethers, leading to the corresponding β-amino ethers. In addition, non-natural α-amino acids could also be obtained in excellent yields with this method.

Guest-Adaptable and Water-Stable Peptide-Based Porous Materials by Imidazolate Side Chain Control

Abstract: The peptide-based porous 3D framework, ZnCar, has been synthesized from Zn2+ and the natural dipeptide carnosine (β-alanyl-L-histidine). Unlike previous extended peptide networks, the imidazole side chain of the histidine residue is deprotonated to afford Zn–imidazolate chains, with bonding similar to the zeolitic imidazolate framework (ZIF) family of porous materials. ZnCar exhibits permanent microporosity with a surface area of 448 m2 g−1, and its pores are 1D channels with 5 A openings and a characteristic chiral shape. This compound is chemically stable in organic solvents and water. Single-crystal X-ray diffraction (XRD) showed that the ZnCar framework adapts to MeOH and H2O guests because of the torsional flexibility of the main His-β-Ala chain, while retaining the rigidity conferred by the Zn–imidazolate chains. The conformation adopted by carnosine is driven by the H bonds formed both to other dipeptides and to the guests, permitting the observed structural transformations.

Semiconducting π-conjugated systems in field-effect transistors: a material odyssey of organic electronics.

Abstract: Since the discovery of highly conducting polyacetylene by Shirakawa, MacDiarmid, and Heeger in 1977, π-conjugated systems have attracted much attention as futuristic materials for the development and production of the next generation of electronics, that is, organic electronics. Conceptually, organic electronics are quite different from conventional inorganic solid state electronics because the structural versatility of organic semiconductors allows for the incorporation of functionality by molecular design. This versatility leads to a new era in the design of electronic devices. To date, the great number of π-conjugated semiconducting materials that have either been discovered or synthesized generate an exciting library of π-conjugated systems for use in organic electronics. 11 However, some key challenges for further advancement remain: the low mobility and stability of organic semiconductors, the lack of knowledge regarding structure property relationships for understanding the fundamental chemical aspects behind the structural design, and realization of desired properties. Organic field-effect transistors (OFETs) are a kind of device consisting of an organic semiconducting layer, a gate insulator layer, and three terminals (drain, source, and gate electrodes). OFETs are not only essential building blocks for the next generation of cheap and flexible organic circuits, but they also provide an important insight into the charge transport of πconjugated systems. Therefore, they act as strong tools for the exploration of the structure property relationships of πconjugated systems, such as parameters of field-effect mobility (μ, the drift velocity of carriers under unit electric field), current on/off ratio (the ratio of the maximum on-state current to the minimum off-state current), and threshold voltage (the minimum gate voltage that is required to turn on the transistor). 17 Since the discovery of OFETs in the 1980s, they have attracted much attention. Research onOFETs includes the discovery, design, and synthesis of π-conjugated systems for OFETs, device optimization, development of applications in radio frequency identification (RFID) tags, flexible displays, electronic papers, sensors, and so forth. It is beyond the scope of this review to cover all aspects of π-conjugated systems; hence, our focus will be on the performance analysis of π-conjugated systems in OFETs. This should make it possible to extract information regarding the fundamental merit of semiconducting π-conjugated materials and capture what is needed for newmaterials and what is the synthesis orientation of newπ-conjugated systems. In fact, for a new science with many practical applications, the field of organic electronics is progressing extremely rapidly. For example, using “organic field effect transistor” or “organic field effect transistors” as the query keywords to search the Web of Science citation database, it is possible to show the distribution of papers over recent years as shown in Figure 1A. It is very clear

Cocatalysts for Selective Photoreduction of CO2 into Solar Fuels.

Abstract: Photoreduction of CO2 into sustainable and green solar fuels is generally believed to be an appealing solution to simultaneously overcome both environmental problems and energy crisis. The low selectivity of challenging multi-electron CO2 photoreduction reactions makes it one of the holy grails in heterogeneous photocatalysis. This Review highlights the important roles of cocatalysts in selective photocatalytic CO2 reduction into solar fuels using semiconductor catalysts. A special emphasis in this review is placed on the key role, design considerations and modification strategies of cocatalysts for CO2 photoreduction. Various cocatalysts, such as the biomimetic, metal-based, metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area. This Review provides useful information for the design of highly selective cocatalysts for photo(electro)reduction and electroreduction of CO2 and complements the existing reviews on various semiconductor photocatalysts.

Functional oligothiophenes: molecular design for multidimensional nanoarchitectures and their applications.

Abstract: 3.2. Thienothiophenes 1216 3.2.1. Thieno[3,4-b]thiophene Analogues 1216 3.2.2. Thieno[3,2-b]thiophene Analogues 1217 3.2.3. Thieno[2,3-b]thiophene Analogues 1218 3.3. , ′-Bridged Bithiophenes 1219 3.3.1. Dithienothiophene (DTT) Analogues 1220 3.3.2. Dithieno[3,2-b:2′3′-d]thiophene-4,4-dioxides 1221 3.3.3. Dithienosilole (DTS) Analogues 1221 3.3.4. Cyclopentadithiophene (CPDT) Analogues 1221 3.3.5. Nitrogen and Phosphor Atom Bridged Bithiophenes 1222