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Spectral investigations of the new organic semiconductor of the formula (TMTSF)(2)[3,3'-Co(1,2-C(2)B(9)H(11))(2)], were performed using Raman and quantum chemical simulation methods. The polarized Raman spectra of single crystals of the salt were recorded in the range 150-3100 cm(-1). An assignment of the strongest vibrational Raman lines was propo...
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... H 11 ) 2 ] salt has an eclipsed configuration of the carborane cages (transoid con- formation). Because there are two possible rotamers of the Co an- ion -designated as cisoid and transoid configurations, we have performed the DFT calculations for both of them and compare the results to the experimental spectrum of the reference material. In the Fig. 1 the optimized geometries of both conformations are presented. The main difference is that the angle between terminal boron/hydrogen and cobalt atom is 180° in the transoid configura- tion while in cisoid configuration, carborane cages are slightly bent in respect to each other and the above mentioned angle is equal 177°. The calculated ...
Citations
... Based on a previous computational study of CoSAN, [23] most of the Raman bands likely originate from the carboranyl component. The coordination of different metal centres results in shifting of several key vibrational modes within the Raman spectrum. ...
Multiplex optical detection in live cells is challenging due to overlapping signals and poor signal‐to‐noise associated with some chemical reporters. To address this, the application of spectral phasor analysis to stimulated Raman scattering (SRS) microscopy for unmixing three bioorthogonal Raman probes within cells is reported. Triplex detection of a metallacarborane using the B−H stretch at 2480–2650 cm⁻¹, together with a bis‐alkyne and deuterated fatty acid can be achieved within the cell‐silent region of the Raman spectrum. When coupled to imaging in the high‐wavenumber region of the cellular Raman spectrum, nine discrete regions of interest can be spectrally unmixed from the hyperspectral SRS dataset, demonstrating a new capability in the toolkit of multiplexed Raman imaging of live cells.
... The Raman spectrum of 1 generated from powder shows various molecular vibrations assigned to B-H bending (1015 cm -1 ) (Jotham and Reynolds 1971) and C-H (1160-1590 cm -1 ) as well as Mo-N, C-C, CO deformation and stretching (Schwarze et al. 2019) and B-H (2500-2600 cm -1 ) (Barszcz et al. 2010) stretching modes (Fig. 10). This unique pattern of Raman bands was used to identify 1 in MCF-7 cells, and revealed an almost identical pattern of Raman peaks compared with the powder control (blue), indicating a relatively high stability of 1 under the applied conditions. ...
... The Raman spectrum of 2 (blue curve, Fig. 12, left) recorded from powder shows also various peaks, which are attributed to B-H deformation and stretching vibrational modes as well as C-H stretching (3055-3085 cm -1 ) (Jotham and Reynolds 1971;Barszcz et al. 2010). The average Raman spectrum of 2 extracted from treated MCF-7 cells (black curve) demonstrates the signal resulting from compound 2 (blue) and the cytoplasm simultaneously. ...
We report on the unique self-assembling properties of one molybdacarborane (1) and two ruthenacarborane complexes (2 and 3) to spontaneously form nanoparticles alone or in combination with bovine serum albumin (BSA) in a 10:1 molar ratio (BSA:metallacarborane). The maverick behaviour of the metallacarboranes in aqueous media was investigated using several spectroscopic techniques, including nanoparticle tracking analysis, UV-Vis, fluorescence, Rayleigh light scattering and NMR spectroscopy, as well as MALDI-TOF mass spectrometry, from which a molecular picture of the nanoparticles was developed. The metallacarborane–albumin nanoparticles showed optimal stability in phosphate buffer (pH 7.4), retaining a mostly monomodal dispersion over 24 h, in contrast to the highly polydispersed nanoparticles of 1–3 alone. The three metallacarboranes were tested in vitro against the MCF-7 (breast carcinoma) cell line, using a BSA-free and a BSA-containing formulation. Surprisingly, the latter induced a significant increase in the cytotoxicity of 1, whereby it did not greatly affect the activity profile of 2 and 3. Finally, label-free confocal Raman imaging was applied to visualise the uptake of the metallacarboranes into single cells. The size of intracellular aggregates in the cytoplasm ranged from 300 nm to 5 μm. The discussed formulation concept is proposed as a new method to increase the bioactivity and the biological stability of poorly water-soluble (metalla)carboranes.
... The electron-molecular coupling constants were evaluated via the isolated dimer model [18]. Barszcz et al. reported the polarized Raman spectra of TMTSF salt of cobalt bis (dicarbollide) anion [19]. They assigned most of the strong Raman lines and two rotamers of Co anion. ...
Theoretical molecular structures and IR and Raman spectra of di and tetra methyl substituted tetrathiafulvalene and tetraselenafulvalene molecules have been studied. These molecules belong to the organic conductor family and are immensely used as building blocks of several organic conducting devices. The Hartree-Fock and density functional theory with exchange functional B3LYP have been employed for computational purpose. We have also performed normal coordinate analysis to scale the theoretical frequencies and to calculate potential energy distributions for the conspicuous assignments. The exciting frequency and temperature dependent Raman spectra have also presented. Optimization results reveal that the sulphur derivatives possess boat shape while selenium derivatives possess planner structures. Natural bond orbitals analysis has also been performed to study second order interaction between donors and acceptors and to compute molecular orbital occupancy and energy.
... So far, only one reference can be found in the literature that deals with computational Raman studies. 38 In this case, the comparison between experimental and theoretical Raman spectra is used to determine the geometry in the solid state. Moreover, it is possible to assign all the frequencies in the spectra to the different vibrations within the molecule with the aid of computed values. ...
This tutorial review will deal with the study of metallacarboranes and their interactions with other molecules from a theoretical point of view. This contribution is devoted to guide experimental chemists through calculations that some years ago were reserved to theoretical specialists. The widespread availability of fast computers enables nowadays studies of complex compounds (e.g. metallacarboranes) from different perspectives including simulation of NMR, infrared or Raman spectra and calculation of other properties such as atomic charges or inter-/intramolecular interactions. The insights gained on the basis of theoretical calculations are crucial for either finding novel or improving existing applications of metallacarboranes. For example, in the case of enzyme inhibitors, the interactions of the metallacarboranes with the surrounding protein and how the interaction affects the efficiency are difficult problems to study experimentally. The use of theoretical tools can provide a detailed understanding of the physico-chemical basis of the interactions and thus offers a chance to control the overall process.
Multiplex optical detection in live cells is challenging due to overlapping signals and poor signal‐to‐noise associated with some chemical reporters. To address this, the application of spectral phasor analysis to stimulated Raman scattering (SRS) microscopy for unmixing three bioorthogonal Raman probes within cells is reported. Triplex detection of a metallacarborane using the B−H stretch at 2480–2650 cm ⁻¹ , together with a bis ‐alkyne and deuterated fatty acid can be achieved within the cell‐silent region of the Raman spectrum. When coupled to imaging in the high‐wavenumber region of the cellular Raman spectrum, nine discrete regions of interest can be spectrally unmixed from the hyperspectral SRS dataset, demonstrating a new capability in the toolkit of multiplexed Raman imaging of live cells.
Metallacarboranes (carboranes incorporating one or more metal atoms in the cage framework, alternatively described as metal-carborane complexes), comprise a huge family of compounds of which thousands have been prepared and characterized. This chapter presents a detailed summary of this area in its many facets, including methods of synthesis, molecular and electronic structures, physical properties, and reactivity. An overview of general synthetic approaches is followed by a review of the preparation, structures, and properties of the smaller (6- and 7-vertex) metallacarboranes, intermediate-sized 8-11 vertex clusters, the 12-vertex icosahedral systems, and finally the supraicosahedral (13- to 15-vertex) cages.
Computations based on quantum chemistry, particularly density functional theory methods, have provided valuable insights into the structure, bonding, thermochemistry, and chemical reactivity of diverse polyhedral metallaboranes. Examples of such computations are provided for metallaboranes having central polyhedra with five to 16 vertices.
