John Burgess

Bio: John Burgess is an academic researcher from University of Leicester. The author has contributed to research in topics: Aqueous solution & Solvation. The author has an hindex of 23, co-authored 344 publications receiving 3002 citations. Previous affiliations of John Burgess include University of Seville.

Template Synthesis of Macrocyclic Compounds

Abstract: Template Processes. Template Synthesis of Polyazamacrocyclic Compounds. Template Synthesis of Macrocyclic Systems Based on di- and Polyamines, and Polyfunctional Dicarbonyl Compounds. Template Synthesis of Three-Dimensional Macrocyclic Systems. Phosphorus- and Arsenic-Containing Macrocyclic Compounds. Crown Ethers and Related Compounds. Covalent Template Synthesis. Polynucleating Macrocyclic Compounds. Other Macrocyclic Compounds. Uses of Template Processes and Products. Conclusions.

Solvatochromic behaviour of intramolecular charge-transfer spectra of inorganic diimine complexes

Abstract: The dependence of charge-transfer maxima (vmax) on solvent has been investigated for a variety of diimine (LL) complexes M(CO)4(LL) and Fe(LL)2(CN)2. These and previously published results for compounds of this general type are collated and summarised in the form of solvent sensitivities, which are the slopes of plots vmaxversus solvent ET values. The dependence of such solvent sensitivities on the nature of the metal, of the diimine ligand, and of other ligands present, is discussed.

Solvatochromic Dyes as Solvent Polarity Indicators

Abstract: This review compiles positively and negatively solvatochromic compounds which have been used to establish empirical scales of solvent polarity by means of UV/vis/near-IR spectroscopic measurements in solution-with particular emphasis on the E ~ ( 3 0 ) scale derived from negatively solvatochromic pyridinium N-phenolate betaine dyes. This requires a short discussion of the concept of solvent polarity and how empirical parameters of solvent polarity can be derived and understood in the framework of linear free-energy relationships. The preconditions for the occurrence of solvatochromism, and further requirements of solvatochromic compounds for them to be useful as solvent polarity indicators will be discussed. In addition to spectroscopically based single parameters of solvent polarity, multiparameter treatments of solvent effects by means of solvatochromic parameters will also be mentioned. The mutual interrelation between some of the more important W/vis/near-IR spectroscopically derived solvent scales, and their correlations with solvatochromic multiparameter equations will be exemplarily given.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Noncovalent synthesis using hydrogen bonding

Abstract: Hydrogen bonds are like human beings in the sense that they exhibit typical grouplike behavior. As an individual they are feeble, easy to break, and sometimes hard to detect. However, when acting together they become much stronger and lean on each other. This phenomenon, which in scientific terms is called cooperativity, is based on the fact that 1+1 is more than 2. By using this principle, chemists have developed a wide variety of chemically stable structures that are based on the reversible formation of multiple hydrogen bonds. More than 20 years of fundamental studies on these phenomena have gradually developed into a new discipline within the field of organic synthesis, and is nowadays called noncovalent synthesis. This review describes noncovalent synthesis based on the reversible formation of multiple hydrogen bonds. Starting with a thorough description of what the hydrogen bond really is, it guides the reader through a variety of bimolecular and higher order assemblies and exemplifies the general principles that determine their stability. Special focus is given to reversible capsules based on hydrogen-bonding interactions that exhibit interesting encapsulation phenomena. Furthermore, the role of hydrogen-bond formation in self-replicating processes is actively discussed, and finally the review briefly summarizes the development of novel materials (nanotubes, liquid crystals, polymers, etc.) and principles (dynamic libraries) that recently have emanated from this intriguing field of research.

Solvothermal in situ metal/ligand reactions: a new bridge between coordination chemistry and organic synthetic chemistry.

Abstract: Several important solvothermal (including hydrothermal) in situ metal/ligand reactions and their mechanisms, including dehydrogenative carbon−carbon coupling, hydroxylation of aromatic rings, cycloaddition of organic nitriles with azide and ammonia, transformation of inorganic and organic sulfur, as well as the CuII to CuI reduction, are outlined in this Account. The current progress clearly demonstrates the important potential of such reactions in the crystal engineering of functional coordination compounds and one-pot synthesis of some unusual organic ligands that are inaccessible or not easily obtainable via conventional methods, thereby substantiating our expectation that a new bridge has been created between coordination chemistry and synthetic organic chemistry.