DMSO Complexes Research Articles

Experimental determination of the relationship between S=O bond length and its stretching frequency of the DMSO molecule

Abstract Time-of-flight neutron diffraction, x-ray diffraction, and attenuated total reflection infrared spectroscopic measurements have been carried out for pure deuterated dimethylsulfoxide (DMSO-d6), concentrated 20 mol% lithium bis(trifluorosulfonyl)amide–DMSO-d6, 14 mol% LiCl–DMSO, and 3 mol% NiCl2–DMSO solutions in order to obtain the relationship between the intramolecular S=O bond length (rSO) and its stretching vibrational frequency (νSO) in the liquid state. The S=O bond length of the DMSO molecule has been determined from the least-squares fitting analysis of neutron and x-ray total interference terms observed in the high Q-region. The νSO–rSO plot that involved the present results and experimental data reported for gaseous and crystalline DMSO as well as DMSO complexes with metal ions has indicated that the νSO–rSO relationship is well approximated by a linear function. The value dνSO/drSO = −3,600 ± 400 cm−1Å−1 was obtained from the slope of the fitted function. It has been revealed that the S=O bond length of the DMSO molecule sensitively reflects the intermolecular interactions that it is receiving from its environment.

Lanthanide Complexes (Ln=La, Nd, Dy) of Octaethyl propane‐1,1,3,3‐tetrayltetrakis(phosphonate): Multidentate Binding Competing with Monodentate DMSO Complexes

AbstractThe preparation of lanthanide nitrate complexes [Ln(NO3)3{L}]n (Ln3+=La, Nd, Dy) supported by the octaethyl propane‐1,1,3,3‐tetrayltetrakis(phosphonate) (L) chelate ligand platform is presented. Re‐crystallization of these compounds from DMSO/THF led to a complete replacement of the multidentate phosphonate ester ligand and the formation of exclusively DMSO‐supported lanthanide nitrate species [Ln(NO3)3(DMSO)4]. The relative basicity of a model phosphonate ester vs. DMSO is explored with theoretical means, pointing out the relevance of solvation in this case in line with the experimentally observed exchange process. The optical properties of the dysprosium(III) derivatives are examined in the visible region indicating a significantly higher quantum yield for its tetraphosphonic ester complex than for the DMSO coordinated analog.

Impact of denticity of chromone/chromene thiosemicarbazones in the ruthenium(II)‐DMSO complexes on their cytotoxicity against breast cancer cells

AbstractDenticity plays a prominent role in the cytotoxicity of metal complexes. The impact of ligand denticity of chromone/chromene thiosemicarbazones (TSCs) in the Ru(II)‐DMSO complexes on the cytotoxicity of cancer cells was evaluated. Ru(II)‐DMSO complex containing tridentate chromone TSC (D1) exhibited better in vitro anticancer activity than the one with bidentate chromene TSC (D2). Using the optimized structures of the complexes, the reason behind the same was attributed to the thermodynamically stable nature of the tridentate system. Hydrolysis study of the complexes showed the kinetically labile nature of the chloride ligand in the tridentate species with respect to the bidentate counterpart. The selective cytotoxicity of complex D1 against breast cancer cells and its less toxicity against normal cells demonstrated the effective anticancer potential of the complex. Further, the binding efficacy of the complexes against DNA and BSA, along with imaging and flow cytometry experiments, warranted the effective cell death induced by the complexes against breast cancer cells via apoptosis.

Syntheses and structural and serum protein protecting activity of ruthenium(ii)–DMSO complexes containing a mercapto ligand

Syntheses and spectral and structural characterization of four new ruthenium(ii) complexes [Ru(mpt)2(DMSO)2] (1), [Ru(mpt)2(bpy)] (2), [Ru(mpt)2(phen)] (3) and [Ru(mpt)2(tptz)] (4) and their serum protein protecting activity have been reported.

Binding mode transformation and biological activity on the Ru(II)-DMSO complexes bearing heterocyclic pyrazolyl ligands

Three Ru(II)-DMSO complexes (1-3) containing 2-(3-pyrazolyl)pyridine (PzPy), 2-pyrazol-3-ylfuran (PzO), or 2-pyrazol-3-ylthiophene (PzS) ligand, were synthesized and characterized. The monodentate coordination of the heterocyclic pyrazolyl ligand (PzPy) with Ru(II) ion via N atom was confirmed by single crystal X-ray diffraction. Complex 1 could be converted to the known η2-bidentate PzPy complex cis(Cl), cis(S)-[RuCl2(PzPy)(DMSO)2] (4) under reflux conditions. The mechanism underlying binding mode transformation was studied by 1H NMR spectroscopy and density functional theory (DFT) calculations. The binding abilities of the complexes (1–4) with calf-thymus (CT) DNA and bovine serum albumin (BSA) were investigated using spectroscopic and molecular docking techniques. Among the four Ru(II) complexes, complexes 1 and 3 inhibited the long-term proliferation of human breast cancer cells, whereas complexes 2 and 4 did not inhibit their proliferation to a considerable extent. Interestingly, complexes 1 and 3 did not induce significant cell death but rather attenuated the clonogenicity of breast cancer cells by upregulating reactive oxygen species (ROS), endoplasmic reticulum (ER) and autophagic stress.

On the molecular basis of H2O/DMSO eutectic mixtures by using phenol compounds as molecular sensors: a combined NMR and DFT study.

NMR and DFT studies of phenol compounds as molecular sensors were carried out to investigate H2O/DMSO eutectic mixtures at a molecular level. The experimental 1H NMR chemical shifts of the OH groups, δexp(OH), of phenol, paracoumaric acid, and vanillic acid show maximum deshielding and, thus, hydrogen bond interactions in the range of mole fractions 0.20 < χ(DMSO) < 0.33. In the mole fractions χ(DMSO) < 0.2, a progressive decrease in δexp(OH) was observed which demonstrates a decrease in hydrogen bond interactions at infinite dilution in H2O, despite the increase in the number of available hydrogen bond acceptor and donor sites. DFT calculated δcalc(OH) of minimum energy solvation clusters were shown to be in reasonable agreement with the pattern in experimental δexp(OH) data. The chemical shift deshielding and, thus, increased hydrogen bond interactions in the natural product + DMSO + nH2O (n = 2, 3) solvation clusters, relative to complexes in DMSO or H2O solutions, cannot be attributed to a single structural parameter of the cooperative interactions between H2O and DMSO molecules with the phenol OH groups of the natural products. The minimum energy conformers of phenol compounds + 2H2O + DMSO complexes are in excellent agreement with a recent low temperature neutron diffraction experiment of 3D2O + DMSO and demonstrate a general structural motif of solvation complexes. The combined use of 1H NMR and DFT studies with emphasis on δ(OH) of phenol compounds, as molecular sensors, can provide an effective method for the study of solute-solvent interactions at the atomic level.

Ru(ii)- and Ru(iv)-dmso complexes catalyze efficient and selective aqueous-phase nitrile hydration reactions under mild conditions

Synthesis and characterization of new water-soluble Ru(ii)- and Ru(iv)-dmso complexes are reported which show good efficiency and selectivity for aqueous-phase nitrile hydration at 60 °C in air. Best performance is achieved using complex [RuCl2(dmso)3(NH3)]·PF6·Cl (3).

DMSO Intercalation in Selected Kaolinites: Influence of the Crystallinity

The present study deals with the relation between crystalline order in kaolinites and their ability to intercalate DMSO. Raw clays and kaolinite–DMSO complexes are analyzed using FTIR, XRD powder diffraction and differential scanning calorimetry and thermogravimetric analysis (DSC-TGA). The crystallinity is accessed using the Hinckley index (HI) from the raw clays’ XRD patterns and the p2 factor from their FTIR spectra. The intercalation ratio is evaluated from XRD and compared among the samples. The thermal analyses show a decrease in the dehydroxylation temperature in the DMSO–kaolinite complexes, indicating a decrease in the interlayer cohesion that may be useful to improve the delamination of kaolinite. The analysis of the coherent scattering domain size in the raw and the DMSO-intercalated samples indicates that the ordering is not affected during the DMSO intercalation. From these results, it is deduced that DMSO intercalation is favored by an increased crystallinity, as revealed by the intercalation ratio from XRD and the DSMO release during DSC-TGA analysis.

A Theoretical and Experimental Study on Hydrogen-bonding Interactions between 4H-1,2,4-triazole-3,5-diamine and DMSO/water

In this paper, 4TZDA-DMSO/water complexes formed by hydrogen bonding interactions were investigated by a combined experimental and computational approach. Two conformations of 4TZDA molecule were considered. Seven hydrogen-bonded 4TZDA-DMSO/H2O complexes were characterized in terms of geometries, energies and vibrational frequencies. The optimizations and calculations were performed for the complexes by Density Functional Theory. In the experimental part, the DMSO/H2O solutions of 4TZDA were prepared and infrared spectra of the solutions were recorded. After the solvation process, significant shifts in the existing bands and new band rising were observed in the experimental spectra of 4TZDA. Following results are found from this study: 1) 4TZDA (I) is more stable than 4TZDA (II). 2) Seven 4TZDA-DMSO and 4TZDA-H2O complexes are investigated and it is seen that all nitrogen atoms of 4TZDA are hydrogen bond acceptor and all hydrogen atoms are hydrogen bond donors. 3) Aqueous complexes of 4TZDA are found to form stronger hydrogen bonds compared to DMSO complexes. 4) It is determined that the most stable structures are intermolecular interactions of lpO⋯H-N and lpN⋯H-O type for the complexes. For these interactions, h-bond lengths are calculated as 1.78 and 1.90 Å and interaction energies are -7.10 kJ/mol for 4TZDA-DMSO and -50.5 kJ/mol for 4TZDA-H2O. Because of this energy difference in the complexes, it can be said 4TZDA forms more stable complexes with water molecules compared to DMSO molecules and with this property, it is an ideal molecule for pharmacological purposes.

Synthesis, spectroscopic characterization and computational study of Ru(II)/DMSO complexes with monocoordinated carbazate ligands

Reaction of the precursor cis,fac-[RuCl2(dmso-S)3(dmso-O)] with three carbazate ligands led to new compounds of the type cis,fac-[RuCl2(dmso-S)3(L)] (L = benzylcarbazate (bc), 1; 4-methoxybenzylcarbazate (mc), 2; or 3,5-dimethoxy-α,α-dimethylbenzylcarbazate (mmc), 3). Complexes 1–3 have been characterized by elemental analysis (CHN), FTIR, UV–vis, and 1H and 13C{1H} NMR spectroscopy. Complex 1 was also analyzed by single-crystal X-ray diffraction and theoretical calculations were performed in order to better understand its spectroscopic data and electronic structure. All collected data were consistent with substitution of one dmso ligand by a monodentate carbazate ligand. Preliminary biological assays against breast and prostate human cancer cell lines were performed in order to evaluate the cytotoxic activity of these three new complexes.

New Ru(II)–DMSO complexes containing coumarin-N-acylhydrazone hybrids: Synthesis, X-ray structures, cytotoxicity and antimicrobial activities

Four novel coumarin-N-acylhydrazone hybrid ligands HL2-5 [(E)-7-(diethylamino)-N′-(4-R-benzylidene)-2-oxo-2H-chromene-3-carbohydrazide, where R = H: HL2; Cl: HL3; Br: HL4 and OCH3: HL5] were obtained from condensation reactions of HL1 (7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide) and p-substituted aldehydes. The reactions of HL2-5 with cis-[RuCl2(DMSO)4] in ethanol resulted in the Ru(II) complexes C2-5 of the type trans-Cl-[RuCl2(DMSO)2(HLn)]. Concomitantly, hydrolysis of the ligand occurred, affording complex C1trans-Cl-[RuCl2(DMSO)2(HL1)]. X-ray diffraction analyses revealed E/Z isomerization of the coumarin-N-acylhydrazones upon coordinating with Ru(II). C2-5 exhibit the Ru(II) atom in a distorted octahedral geometry with the ligand HL coordinated in the keto form through the hydrazone carbonyl and the iminic nitrogen. Ligands (HL1-5) and Ru(II)–DMSO complexes (C1-5) were screened for their antiproliferative activities. In general, the free ligands were more cytotoxic than the Ru(II) complexes, possibly caused by lower membrane permeation capacity of the latter and different mechanism of action than those displayed by the ligands. Amongst coumarin-N-acylhydrazone ligands, the highest potency of HL4 (IC50 = 16.1 and 11.9 μM for 4T1 and B16-F10, respectively) was associated to its better lipophilicity, caused by a -Br substituent. Antimicrobial assays towards gram-positive and gram-negative strains showed that only HL1 and complexes C2-5 were soluble in the agar gel culture media. C4 (R = Br) was the most effective compound (MIC = 40.5 μM for Staphylococcus aureus), also correlated to lipophilic parameters.

Raman bandshape analysis and DFT study of C[dbnd]O and C[sbnd]H stretching modes of NN-Dibutyl formamide in DMSO solvent`

The study reports the inter-molecular interactions and dynamics of CO and CH stretching modes of NN- Dibutyl Formamide (DBF) in DMSO solvent using Raman spectroscopic technique. The Raman band of CO and CH stretching modes have been deconvoluted into two distinct bands for neat as well as in DMSO solvent. Peak wavenumbers of CO stretching modes show red shift while CH stretching modes shows blue shift with the increase in solvent concentrations. The optimized geometric parameters, vibrational wavenumbers, Mulliken atomic charges and natural bond orbitals of the molecule has been computed using Density Functional Theory (DFT) method with basis set 6-31 +G (d, p). In addition, the same basis set has been carried out with counterpoise keyword accounting BSSE calculation on monomer and dimer states with DMSO solvent to present an appropriate interacting environment. IEF-PCM solvation model has also been computed using the same basis set and compares the geometrical parameters and vibrational wavenumbers of the molecules and in their complexes. In order to get a complete study of the DBF + DMSO complexes, explicit solvation model has also been calculated for Monomer DBF in two solvent molecules. Theoretical calculations of frequencies have been compared with the experimental findings and the results are found in good agreement.

Growth of CH3NH3PbI3 Perovskite on Stainless Steel Substrate Layered by ZnO Nanoparticles Using One-Step Spin Coating Route

In this work, we report the preparation of CH3NH3PbI3 perovskite using one-step spin coating route for solar cell application. CH3NH3I• PbI2•DMF•DMSO complexes were coated on stainless steel as a subtrate layered by ZnO nanoparticles as an electron transport layer. To obtain samples with a special performance, we annealed the samples at a temperature of 100, 120, and 140°C for 10 minutes. The samples were then characterized by means of XRD, SEM/EDX, and Spectroscopic Ellipsometry. The analysis of XRD data presented that the CH3NH3PbI3 perovskites were successfully prepared and crystallized in tetragonal structure confirming from crystalline planes (110) and (220). Meanwhile, the particle size of the samples prepared at a temperature of 100, 120, and 140°C presented 42.96, 54.73, and 55.19 nm, respectively with coincide with the SEM images. The results indicated that the increase in temperature during synthesis influenced the particle growth. Furthermore, the characterization using Spectroscopic Ellipsometry exhibited that the CH3NH3PbI3 successfully layered on the substrate sizing nano metric scale that open high opportunity to be applied to solar cells with high performance.

Hydrogen-bonding interactions between 1-butyl-2,3-dimethylimidazolium tetrafluoroborate and dimethyl sulphoxide

In practical use, ionic liquids (ILs) often mix with cosolvents to reduce the high polarity, large viscosity and high cost of pure ILs. Hydrogen-bonding interactions greatly influence the properties of IL-cosolvent system. In this work, the interactions between an IL 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([BMMIM][BF4]) and DMSO have been investigated by attenuated total reflection infrared (ATR-IR) spectroscopy and density functional theory (DFT) calculations. Excess infrared spectroscopy and two-dimensional (2D) correlation infrared spectroscopy were applied to analyze the infrared spectra. It is found that: 1) Hydrogen-bonding interaction is the main cause that induces the infrared spectra change of v(CH) and v(CD). 2) The hydrogen-bonding interactions involving C4,5–H change prior to that of the alkyl CH in [BMMIM][BF4]. 3) The hydrogen atoms in the CH3 attached to N3 are more preferred to be hydrogen-bond donors than the other hydrogen atoms in the [BMMIM]+ cation. 4) The hydrogen-bonds in the [BMMIM]+−[BF4]− and [BMMIM][BF4]−DMSO complexes are the closed shell interaction and are electrostatic dominant.

Synthesis, characterization and biological evaluation of ruthenium flavanol complexes against breast cancer

Four Ru(II) DMSO complexes (M1R-M4R) having substituted flavones viz. 3-Hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (HL1), 3-Hydroxy-2-(4-nitrophenyl)-4H-chromen-4-one (HL2), 3-Hydroxy-2-(4-dimethylaminophenyl)-4H–chromen-4-one (HL3) and 3-Hydroxy-2-(4-chlorophenyl)-4H-chromen-4-one (HL4) were synthesized and characterized by elemental analysis, IR, UV–Vis, 1H NMR spectroscopies and ESI-MS. The molecular structures of the complexes were investigated by integrated spectroscopic and computational techniques (DFT). Both ligands as well as their complexes were screened for anticancer activities against breast cancer cell lines MCF-7. Cytotoxicity was assayed by MTT [3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. All ligands and their complexes exhibited significant cytotoxic potential of 5–40μM concentration at incubation period of 24h. The cell cytotoxicity increased significantly in a concentration-dependent manner. In this series of compounds, HL2 (IC50 17.2μM) and its complex M2R (IC50 16μM) induced the highest cytotoxicity.

In vitro cytotoxicity and antibacterial studies of ruthenium(II) DMSO complexes with S-allyldithiocarbazate

The ruthenium(II) DMSO complexes with formula [RuCl(DMSO)3L1](1) and [RuCl(DMSO)3L2](2) had been synthesised. The newly synthesised complexes are characterised by elemental analysis, UV-VIS, FT-IR, NMR and ESI-MS spectroscopy. The spectral and analytical data of the complexes 1 and 2 supports well with the molecular formulae proposed. The in vitro cytotoxicity of these complexes evaluated using MTT assay indicate that the above complexes are more toxic against Hela cervical cancer cell line, but significantly less toxic against the normal Vero cell line. Furthermore, the antibacterial activity of the complexes 1 and 2 against S.aureus and E.Coli had also been tested and compared with standard streptomycin.

Ruthenium(II) DMSO complexes with CˆC* cyclometalated phenylimidazol NHC ligands

We present the synthesis of cyclometalated ruthenium N-heterocyclic carbene (NHC) complexes of the general formula [Ru(CˆC*)(DMSO)3Cl] and their use as starting material for the synthesis of a heteroleptic 2,2′-bipyridine (bpy) complex [Ru(bpy)(CˆC*)(DMSO)Cl]. Starting from the corresponding η6-(p-cymene) complexes [Ru(p-cymene)(CˆC*)Cl], the π-coordinated aryl ligand is substituted by three S-bound dimethyl sulfoxide ligands. In the course of this substitution, the complexes undergo a change in geometry from facial to meridional, which is unambiguously proven by solid state structure determination and DFT calculations. The labile DMSO ligands can be substituted by bidentate ligands as shown for the widely used 2,2′-bipyridine. The resulting air- and moisture-stable heteroleptic complex features two bidentate (CˆC* + bpy) and two monodentate (Cl− + DMSO) ligands.

Synthesis, characterization and biological activities of some Ru(II) complexes with substituted chalcones and their applications as chemotherapeutics against breast cancer

Four new Ru(II) DMSO complexes with substituted chalcone ligands viz. (E)-1-(2-hydroxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (HL1), (E)-1-(2-hydroxyphenyl)-3-(4-nitrophenyl)prop-2-en-1-one (HL2), (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (HL3) and (E)-1-(2-hydroxyphenyl)-3-(4-Chlorophenyl)prop-2-en-1-one (HL4) have been synthesized, and characterized by micro-analyses, IR, 1H NMR, UV–Vis and ESI-MS and screened for anti-cancer activity against breast cancer cell lines (MCF-7 and MDA MB-231). Compounds HL4 and [Ru(HL1) (O-DMSO)3(S-DMSO)]Cl (M1R) showed significant anti-breast cancer activity as evident from cytotoxicity, morphological and nuclear changes, DNA fragmentation and cell cycle arrest in breast cancer cells. UV–Vis and CD-spectra analysis showed HL4 and M1R interfered with DNA absorption spectra possibly due to DNA binding whereas these compounds were devoid of DNA topoisomerase inhibiting activity. Thus, these Ru(II) compounds have been established as new leads for future optimization by improving anti-cancer potency and safety.

Ru(ii)-dmso complexes containing azole-based ligands: synthesis, linkage isomerism and catalytic behaviour.

The reaction of cis,fac-[RuCl2(dmso-S)3(dmso-O)], 1, with different azole (L) ligands leads to new [RuCl2(L)(dmso-S)3] compounds (L = CH3-pz-H, 2; NO2-pz-H, 3; CF3-pz-H, 4 and Br-Hind, 5). Complexes 2-5 have been characterized by analytical, spectroscopic and electrochemical techniques as well as by monocrystal X-ray diffraction analysis. Upon oxidation to Ru(iii) the complexes undergo linkage isomerization of a S-bound dmso ligand and the corresponding kinetic rates as well as the thermodynamic properties have been determined for compound 2 and also for the previously described [Ru(II)Cl2(pypz-H)(dmso-S)2] (pypz-H = 2-(3-pyrazolyl)pyridine), 6, from cyclic voltammetries performed at different scan rates. The exposure of compound 2 to visible light in acetonitrile produces the substitution of one dmso ligand by a solvent molecule generating a new compound, 2'. The irradiation of solutions of compounds 2 and 6 in chloroform leads in both cases to the substitution of one dmso by a chlorido ligand in parallel to the oxidation of Ru(ii) to Ru(iii) generating complexes 2'' and 6' respectively. The reactivity of compounds 2-6 has been tested with regard to the hydration of nitriles in water as a solvent, displaying in all cases good performance and selectivity for the corresponding amides.

Synthesis, characterization and antiproliferative activity of amino- and DMSO complexes of platinum(II) containing l-carnitine

l-Carnitine, a biomolecule able to cross the blood–brain barrier exploiting specific transporters, behaves as mono or bidentate anionic ligand for Pt(II) in the new amino complexes cis-[Pt(l-carnitine-O)2(NH3)2](BF4)2 (1), cis-[PtCl(l-carnitina-O)(NH3)2]BF4 (2), [Pt(l-carnitine-O,O′)(1,2-DACH)]BF4 (3), [Pt(l-carnitine-O)2(1,2-DACH)](BF4)2 (4), and [PtCl(l-carnitine-O)(1,2-DACH)](BF4) (5). Four complexes with DMSO have been also prepared and characterized: the synthetic intermediate [Pt(CO3)(DMSO)2] (6), [Pt(l-carnitine-O,O′)(DMSO)2]BF4 (7), cis-[Pt(l-carnitine-O)2(DMSO)2](BF4)2 (8) and cis-[PtCl(l-carnitine-O)(DMSO)2]BF4, (9).The antiproliferative activity of three representative complexes 1, 5 and 7 has been assayed against three human cancer cell lines A2780, K562 and SKOV3, and it was found comparable to that of the parent active compounds cis-[PtCl2(1,2-DACH)] and cisplatin.