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Synthesis and crystallographic and spectroscopic structural characterization, along with spectral band assignments calculated by using density functional theory (M06L/cc-pVDZ and B3LYP/6-31G(d)), are reported for Fe(OEP)picrate as a model for hemozoin (malaria pigment) and its synthetic analog β-hematin, which are spectroscopically identical. The average Fe–N distance, 2.044(12) A, and the Raman modes indicate a high-spin five-coordinate iron(III) complex. Resonance enhancement is observed for the totally symmetric oxidation state marker band ν4 along with the characteristic bands of Cβ-substituted hemes in the ranges of 1621–1639 cm−1 for νas(CαCm) and 750–756 cm−1 for ν(pyr breathing) similar to β-hematin and hemozoin when using near-IR excitation wavelengths. The similarity of the resonance Raman spectral profiles for Fe(OEP)picrate and β-hematin, along with the structural results, indicates that Fe(OEP)picrate is an excellent model for understanding the stereochemistry and intermolecular interaction of β-hematin. Copyright © 2017 John Wiley & Sons, Ltd.

Computational modeling was applied to far-infrared (FIR) spectra of Pt-based anticancer drugs to study the hydrolysis of these important molecules. Here, we present a study that investigates the influence of different factors-basis sets on non-Pt atoms, relativistic effective core potentials (RECPs) on the Pt atom, density functional theory (DFT) functionals, and solvation models-on the prediction of FIR spectra of two Pt-based anticancer drugs, cisplatin and carboplatin. Geometry optimizations and frequency calculations were performed with a range of functionals (PBE, PBE0, M06-L, and M06-2X), Dunning's correlation-consisted basis sets (VDZ, VTZ, aVDZ, and aVTZ), RECPs (VDZ-pp, VTZ-pp, aVDZ-pp, and aVTZ-pp), and solvation models (IEFPCM, CPCM, and SMD). The best combination of the basis set/DFT functional/solvation model was identified for each anticancer drug by comparing with experimentally available FIR spectra. Different combinations were established for cisplatin and carboplatin, which was rationalized by means of the partial atomic charge scheme, ChelpG, that was utilized to study the charge transfer between the Pt ion and ligands in both cisplatin and carboplatin.

Cyclopropane fatty acids (CFAs) are a group of lipids with unique physical and chemical properties between those of saturated and monounsaturated fatty acids. The distinctive physicochemical characteristics of CFAs (e.g. oxidative stability, self-polymerization at high temperatures, etc.) results from the presence of a cyclopropane ring within their structure making them highly useful in industrial applications. CFAs are present in several species of plants and bacteria and are typically detected with standard lipid profiling techniques, such as gas or liquid chromatography. In this work we investigated several strains of S. cerevisiae, genetically modified to introduce the production of CFAs, in comparison to control strain using confocal Raman spectroscopy (CRS). The aim of our work was to demonstrate the potential of CRS not only to detect changes introduced due to the CFAs presence, but also to track CFAs within the cells. We present for the first time Raman and IR spectra of CFA standard (cis-9,10-methyleneoctadecanoic acid), completed with quantum chemical calculations and band assignment. We identified marker bands of CFA (e.g. 2992, 1222, 942 cm-1) attributed to the vibrations of the cyclopropyl ring. Furthermore, we analysed lipid bodies (LBs) from modified and control yeast using CRS imaging and identified multiple changes in size, number and composition of LBs from engineered strains. We observed a significant reduction in the degree of unsaturation of LBs using the ratio of bands located at 1660 cm-1 (ν(C[double bond, length as m-dash]C)) and 1448 cm-1 (δ(CH2)) in the modified cell lines. In addition, we were able to detect the presence of CFAs in LBs, using the established marker bands. CRS shows tremendous potential as technique to identify CFAs in lipid bodies providing a new way to track lipid production in genetically modified single yeast cells.

A series of dialkylphenylphosphines and their analogous aniline substrates have been metallated with the synergistic mixed-metal base [(TMEDA)Na(TMP)(CH2 SiMe3 )Mg(TMP)] 1. Different metallation regioselectivities for the substrates were observed, with predominately lateral or meta-magnesiated products isolated from solution. Three novel heterobimetallic complexes [(TMEDA)Na(TMP)(CH2 PCH3 Ph)Mg(TMP)] 2, [(TMEDA)Na(TMP)(m-C6 H4 PiPr2 )Mg(TMP)] 3 and [(TMEDA)Na(TMP)(m-C6 H4 NEt2 )Mg(TMP)] 4 and two homometallic complexes [{(TMEDA)Na(EtNC6 H5 )}2 ] 5 and [(TMEDA)Na2 (TMP)(C6 H5 PEt)]2 6 derived from homometallic metallation have been crystallographically characterised. Complex 6 is an unprecedented sodium-amide, sodium-phosphide hybrid with a rare (NaNNaP)2 ladder motif. These products reveal contrasting heterobimetallic deprotonation with homometallic induced ethene elimination reactivity. Solution studies of metallation mixtures and electrophilic iodine quenching reactions confirmed the metallation sites. In an attempt to rationalise the regioselectivity of the magnesiation reactions the C-H acidities of the six substrates were determined in THF solution using DFT calculations employing the M06-2X functional and cc-pVTZ Dunning's basis set.