Lauren E. Hatcher

Bio: Lauren E. Hatcher is an academic researcher from University of Bath. The author has contributed to research in topics: Linkage isomerism & Hydrogen bond. The author has an hindex of 14, co-authored 33 publications receiving 540 citations. Previous affiliations of Lauren E. Hatcher include Cardiff University & Rutherford Appleton Laboratory.

A rapidly-reversible absorptive and emissive vapochromic Pt(II) pincer-based chemical sensor

Abstract: Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses.

Hingeless Negative Linear Compression in the Mechanochromic Gold Complex [(C6F5Au)2(μ‐1,4‐diisocyanobenzene)]

Abstract: The compression of a crystalline material under hydrostatic pressure always results in a reduction in volume of the solid, with the observed reduction typically occurring in all crystallographic cell parameters.1 However, there are a number of exceptional materials that have been shown to expand in a specific direction upon hydrostatic compression while maintaining a positive volume compression. The phenomenon of uni-or biaxial expansion under compression is known as negative linear compressibility (NLC).1 Rare examples of NLC have attracted attention recently owing to the potential applications in a range of materials, including body armor, artificial muscle actuators, and pressure sensors.2

Metastable linkage isomerism in [Ni(Et4dien)(NO2)2]: a combined thermal and photocrystallographic structural investigation of a nitro/nitrito interconversion.

Abstract: One way or another: The N‐bound NO2 group in [Ni(Et4dien)(η2‐O,ON)(η1‐NO2)] (see structure Ni turquoise, N blue, O red) has been shown to undergo reversible conversion into the O‐bound nitrito linkage isomer under both thermal and photoactivation of a single crystal. Et4dien=N,N,N′,N′‐tetraethyldiethylenetriamine.

Steady‐State and Pseudo‐Steady‐State Photocrystallographic Studies on Linkage Isomers of [Ni(Et4dien)(η2‐O,ON)(η1‐NO2)]: Identification of a New Linkage Isomer

Abstract: At temperatures below 150 K, the photoactivated metastable endo‐nitrito linkage isomer [Ni(Et4dien)(η2‐O,ON)(η1‐ONO)] (Et4dien=N,N,N′,N′‐tetraethyldiethylenetriamine) can be generated with 100 % conversion from the ground state nitro‐(η1‐NO2) isomer on irradiation with 500 nm light, in the single crystal by steady‐state photocrystallographic techniques. Kinetic studies show the system is no longer metastable above 150 K, decaying back to the ground state nitro‐(η1‐NO2) arrangement over several hours at 150 K. Variable‐temperature kinetic measurements in the range of 150–160 K show that the rate of endo‐nitrito decay is highly dependent on temperature, and an activation energy of Eact=+48.6(4) kJ mol−1 is calculated for the decay process. Pseudo‐steady‐state experiments, where the crystal is continually pumped by the light source for the duration of the X‐ray experiment, show the production of a previously unobserved, exo‐nitrito‐(η1‐ONO) linkage isomer only at temperatures close to the metastable limit (ca. 140–190 K). This exo isomer is considered to be a transient excited‐state species, as it is only observed in data collected by pseudo‐steady‐state methods.

On the appearance of nitrite anion in [PdX(OAc)L2] and [Pd(X)(C^N)L] syntheses (X = OAc or NO2): photocrystallographic identification of metastable Pd(η1-ONO)(C^N)PPh3

Abstract: Pd3(OAc)5NO2, an impurity in “Pd(OAc)2” {formally Pd3(OAc)6}, emerges as a serious issue in the synthesis of pure PdII complexes derived from Pd(OAc)2, for example in our C–H activation precatalyst, Pd(OAc)2(pip)2 (pip = piperidine). A previous proposal that nitrite anion can be formed by oxidation of CH3CN by metallic Pd and air, leading to cyclo(ortho)palladated complexes containing nitrite anion, e.g. Pd(NO2)(C^N)L (C^N = papaverine; L = CH3CN or DMSO) can be explained by Pd3(OAc)5NO2 acting as the nitrite source. Finally, photocrystallographic metastable linkage isomerisation and complete conversion to an oxygen-bound nitrito complex Pd(η1-ONO)(C^N)PPh3 has been observed.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal, and cubic phases of methylammonium lead iodide

Abstract: The hybrid halide perovskite ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ exhibits a complex structural behavior, with successive transitions between orthorhombic, tetragonal, and cubic polymorphs around 165 and 327 K. Herein we report first-principles lattice dynamics (phonon spectrum) for each phase of ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$. The equilibrium structures compare well to solutions of temperature-dependent powder neutron diffraction. By following the normal modes, we calculate infrared and Raman intensities of the vibrations, and compare them to the measurement of a single crystal where the Raman laser is controlled to avoid degradation of the sample. Despite a clear separation in energy between low-frequency modes associated with the inorganic (${\mathrm{PbI}}_{3}{}^{\ensuremath{-}}{)}_{n}$ network and high-frequency modes of the organic ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{}^{+}$ cation, significant coupling between them is found, which emphasizes the interplay between molecular orientation and the corner-sharing octahedral networks in the structural transformations. Soft modes are found at the boundary of the Brillouin zone of the cubic phase, consistent with displacive instabilities and anharmonicity involving tilting of the ${\mathrm{PbI}}_{6}$ octahedra around room temperature.

First-principles calculations of electronic structure and spectra of strongly correlated systems: the LDA+U method

Abstract: The generalization of the Local Density Approximation (LDA) method for the systems with strong Coulomb correlations is presented which gives a correct description of the Mott insulators. The LDA+U method is based on the model hamiltonian approach and allows to take into account the non-sphericity of the Coulomb and exchange interactions. parameters. Orbital-dependent LDA+U potential gives correct orbital polarization and corresponding Jahn-Teller distortion. To calculate the spectra of the strongly correlated systems the impurity Anderson model should be solved with a many-electron trial wave function. All parameters of the many-electron hamiltonian are taken from LDA+U calculations. The method was applied to NiO and has shown good agreement with experimental photoemission spectra and with the oxygen Kα X-ray emission spectrum.

Iodine capture in porous organic polymers and metal–organic frameworks materials

Abstract: The enrichment of radioactive iodine in the waste of nuclear industries threatens human health, and thus the efficient capture of iodine has attracted a great deal of attention in recent years. Porous organic polymers (POPs) and metal–organic frameworks (MOFs), new classes of porous materials, act as outstanding candidate adsorbent materials in this field due to their high surface areas, permanent tunable porosities, controllable structures, high thermal/chemical stabilities, versatility in molecular design and potential for post-synthetic modification. Herein, this review focuses on the research progress of these two types of porous materials for highly efficient iodine capture. We analyze and discuss some valid strategies for enhancing their iodine uptake, including increasing their surface area and pore volume, using organic building units with unique configurations and functions, introducing chemical functional groups to provide high-enthalpy binding sites, and further processing of POP and MOF materials. Indeed, there are many special structural and functional features found in porous POP and MOF materials, which make them unique and merit further exploration. Thus, we expect to see their usage grow as this field progresses.