SC Ph Research Articles

Neutral rhenium(I) tricarbonyl complexes with sulfur-donor ligands: anti-proliferative activity and cellular localization.

Rhenium(I) tricarbonyl complexes are widely studied for their cell imaging properties and anti-cancer and anti-microbial activities, but the complexes with S-donor ligands remain relatively unexplored. A series of six fac-[Re(NN)(CO)3(SR)] complexes, where (NN) is 2,2'-bipyridyl (bipy) or 1,10-phenanthroline (phen), and RSH is a series of thiocarboxylic acid methyl esters, have been synthesized and characterized. Cellular uptake and anti-proliferative activities of these complexes in human breast cancer cell lines (MDA-MB-231 and MCF-7) were generally lower than those of the previously described fac-[Re(NN)(CO)3(OH2)]+ complexes; however, one of the complexes, fac-[Re(CO)3(phen)(SC(Ph)CH2C(O)OMe)] (3b), was active (IC50 ∼ 10 μM at 72 h treatment) in thiol-depleted MDA-MB-231 cells. Moreover, unlike fac-[Re(CO)3(phen)(OH2)]+, this complex did not lose activity in the presence of extracellular glutathione. Taken together these properties show promise for further development of 3b and its analogues as potential anti-cancer drugs for co-treatment with thiol-depleting agents. Conversely, the stable and non-toxic complex, fac-[Re(bipy)(CO)3(SC(Me)C(O)OMe)] (1a), predominantly localized in the lysosomes of MDA-MB-231 cells, as shown by live cell confocal microscopy (λex = 405 nm, λem = 470-570 nm). It is strongly localized in a subset of lysosomes (25 μM Re, 4 h treatment), as shown by co-localization with a Lysotracker dye. Longer treatment times with 1a (25 μM Re for 48 h) resulted in partial migration of the probe into the mitochondria, as shown by co-localization with a Mitotracker dye. These properties make complex 1a an attractive target for further development as an organelle probe for multimodal imaging, including phosphorescence, carbonyl tag for vibrational spectroscopy, and Re tag for X-ray fluorescence microscopy.

237 Skin barrier integrity is enhanced after topical application of emulsions with an acidic pH

The pH of the stratum corneum is slightly acidic (mean 4.9) and tightly regulated. This is important for antimicrobial defense and the formation of the physical barrier. The acidic pH inhibits the growth of pathogenic Staphylococcus aureus and enables optimal activity of enzymes for lipid synthesis, epidermal differentiation and desquamation. Here we asked whether topical application of an oil-in-water emulsions adjusted to pH 4 or pH 5.8 and the untreated control influence biophysical markers and mechanical stability of the skin barrier, Stratum corneum morphology and inflammation. Twenty-four healthy volunteers aged 18 to 75 years were treated in a randomized way on the lower arms for 28 days; pH, TEWL, SC hydration, mechanical stability, corneocyte size and inflammation were recorded. After 28 days, skin surface pH was significantly more reduced by the pH 4 compared to the pH 5.8 emulsion. TEWL as a marker of skin barrier function was slightly reduced by both emulsions. SC hydration was significantly increased to the same level by both emulsions. The number of D-Squame® tape-strips to disrupt the skin barrier to a threefold increase in TEWL as a marker for skin integrity was significantly increased by both emulsions compared to untreated control, but slightly more by the pH 4 emulsion. Inflammation after tape-stripping as determined by clinical grading of erythema was considerable reduced by the pH 4 emulsion, and IL-1α protein expression was significantly reduced by both emulsions, but the reduction was higher with the pH 4 preparation. The size of corneocytes attached to the tape-strips as a marker for epidermal differentiation and desquamation was significantly increased after treatment with the pH 4 compared to the pH 5.8 emulsion and the control. In summary, treatment with a pH 4 emulsion positively influenced SC pH, TEWL, SC hydration, epidermal differentiation/desquamation resulting in increased mechanically stability and reduced inflammation against tape-stripping induced irritation.

678 Site-specific microarray evaluation of spontaneous dermatitis in flaky tail mice

Flaky tail mice (FTM) with gene mutations to filaggrin and TMEM79 are known to spontaneously develop atopic dermatitis (AD)-like dermatitis. Interestingly, we have already reported that the spontaneous development of dermatitis exhibits site-specificity, i.e., the face and neck develop spontaneous dermatitis, while the dorsal flank shows normal skin in old FTM. In fact, TEWL and SC pH increased, SC hydration decreased, and epidermis thickened in the neck, but not in the dorsal flank. The detailed pathogenic mechanisms of such site-specific emergence of dermatitis in AD remain unclear. To clarify the pathogenesis of site-specificity, we analyzed skin of the neck and dorsal flank in old FTM using a microarray. Many genes for keratin and keratin-associated protein were up-regulated in the neck compared with the dorsal flank. Several genes thought to be associated with the pathogenesis of AD, such as IL-4, 5, and 13, TSLP, TARC, loricrin, involucrin, transglutaminase 1, TMEM79, defensin, cathelicidin antimicrobial peptide, claudin 1, and EGFR, showed no significant changes between the neck and dorsal flank. In other AD-associated genes, filaggrin was up-regulated in the neck, and some members of the kallikrein and serine peptidase inhibitor family fluctuated. KEGG pathway analysis with DAVID ver. 6.8 revealed the most significant difference in the pathway of S. aureus infection between both sites (P<0.0001). In addition, multiple genes downstream of the peroxisome proliferator-activated receptor (PPAR) signaling pathway were down-regulated (P=0.0039), in line with our previous studies showing therapeutic effects of some PPAR activators in a hapten-induced murine AD model. Although further studies are necessary, the present findings suggest several candidates as genes associated with site-specific emergence of dermatitis in AD, including ones associated with S. aureus infection or PPARs.

Synthesis and structures of cadmium carboxylate and thiocarboxylate compounds with a sulfur-rich coordination environment: carboxylate exchange kinetics involving tris(2-mercapto-1-t-butylimidazolyl)hydroborato cadmium complexes, [Tm(Bu(t))]Cd(O2CR).

A series of cadmium carboxylate compounds in a sulfur-rich environment provided by the tris(2-tert-butylmercaptoimidazolyl)hydroborato ligand, namely, [TmBut]CdO2CR, has been synthesized via the reactions of the cadmium methyl derivative [TmBut]CdMe with RCO2H. Such compounds mimic aspects of cadmium-substituted zinc enzymes and also the surface atoms of cadmium chalcogenide crystals, and have therefore been employed to model relevant ligand exchange processes. Significantly, both 1H and 19F NMR spectroscopy demonstrate that the exchange of carboxylate groups between [TmBut]Cd(κ2-O2CR) and the carboxylic acid RCO2H is facile on the NMR time scale, even at low temperature. Analysis of the rate of exchange as a function of concentration of RCO2H indicates that reaction occurs via an associative rather than dissociative pathway. In addition to carboxylate compounds, the thiocarboxylate derivative [TmBut]Cd[κ1-SC(O)Ph] has also been synthesized via the reaction of [TmBut]CdMe with thiobenzoic acid. The molecular structure of [TmBut]Cd[κ1-SC(O)Ph] has been determined by X-ray diffraction, and an interesting feature is that, in contrast to the carboxylate derivatives [TmBut]Cd(κ2-O2CR), the thiocarboxylate ligand binds in a κ1 manner via only the sulfur atom.

Comparison of two series of non‐invasive instruments used for the skin physiological properties measurements: the ‘Soft Plus’ from Callegari S.p.A vs. the series of detectors from Courage &amp; Khazaka

The invasive measuring techniques are of great help in the evaluation of skin physiological functions and topical formulation. The reproducibility and accuracy of the instrument are crucial. The aim of this study is to reveal the differences and correlations in measuring skin hydration, pH, sebum, elasticity and melanin on the forearm or faces between two commercially available series of instruments. 20 subjects were enrolled to be measured by the two series of instruments. The measurements by each series were performed on the left/right side of the body randomly. The pH, sebum, elasticity and melanin measurements were performed on the faces in different areas, while the hydration measurements were operated on the forearms before and after wet dressing, respectively. Positive correlations were found in the values of skin SC hydration, pH, sebum and melanin detected by the two series. The values related to skin elasticity measured by the two instruments were statistically negative correlated. The Soft Plus series has higher variation in detecting skin hydration, pH, and melanin than the instruments from Courage & Khazaka. The differences of the two series must be instrument related. The difference in level of measurement can be due either to differences in the design of the probe, to differences in time for measurement, to differences in left/right part of the body or a combination of these three. The two series have significant correlations. The instruments from CK are more reproducible.

Effect of immunocastration in group-housed commercial fattening pigs on reproductive organs, malodorous compounds, carcass and meat quality

In the present study, the effect of immunocastration on carcass traits, meat quality, reproductive organs development, and boar taint compounds was investigated. Male piglets (50% Duroc crosses) were randomly assigned to three treatment groups: entire males (EM; n = 19), surgical castrates (SC; n = 20) and immunocastrates (IC, vaccinated with Improvac&lt;sup&gt;&amp;reg;&lt;/sup&gt; at the age of 79 and 142 days; n = 21). Pigs were fed ad libitum and weighed at the time of first and second vaccination and before slaughter (176 days of age). No differences between treatment groups were detected for carcass weight. In the case of backfat thickness, carcass lean meat content, and belly leanness score, IC were intermediate between EM (the leanest) and SC (the fattest), differing (P &amp;lt; 0.05) from both control groups. Regarding loin eye fat area, neck intermuscular fatness, ham leanness, and leaf fat weight, IC were similar to EM and were less fat than SC (P &amp;lt; 0.01). IC had lower intramuscular fat than SC (P &amp;lt; 0.01) and higher average pH 24 than both EM and SC (P &amp;lt; 0.01), resulting in darker colour. IC also demonstrated lower drip loss than EM (P &amp;lt; 0.05). Immunocastration caused a significant reduction of reproductive organs and concentrations of boar taint compounds (P &amp;lt; 0.01) which were comparable with the levels observed for SC. &amp;nbsp;

Diastereoselective Protonation, Substitution and Addition Reactions at Pseudotetrahedral Rhenium Complexes

AbstractThe chiral N,P ligand P(Me)(Ph)[8‐(2‐methylquinolinyl)] (3) was synthesized and separated into its enantiomers via diastereomeric palladium complexes. The reactions of 3 and (RP)‐3 with [CpRe(CO)(NO)(NCMe)]BF4 (7) gave thediastereomeric complexes [CpRe(CO)(NO){P(Me)(Ph)(C10H8N)}]BF4 [8 and (RRe,SP/SRe,SP)‐8], which, upon borohydride reduction, yielded the corresponding methyl complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(CH3)] [9 and (RRe,SP/SRe,SP)‐9]. Treatment of 9 with HBF4 under carefully controlled conditions gave the diastereomerically pure chelates [CpRe(NO){P(Me)(Ph)(C10H8N)}]BF4 [(RRe,SP/SRe,RP)‐10, (RRe,RP/SRe,SP)‐10 and (RRe,SP)‐10]. The chelate ring was opened with NaSH to produce the hydrosulfido complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(SH)] [(RRe,SP/SRe,RP)‐11, (RRe,RP/SRe,SP)‐11 and (RRe,SP)‐11]. Each step in this sequence proceeded with retention of configuration at rhenium. Complex 11 underwent acid‐promoted condensation with aldehydes to give thioaldehyde complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(S=CHR)]BF4 (12a–d, R = Ph, Me, 4‐C6H4OMe, C6F5). The addition of nucleophiles X– to 12a gave rhenium‐coordinated α‐chiral thiolate complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}{SC(H)(Ph)(X)}] (13a–e, X = acac, PhCH2S, EtS, tBuS, CN) with 42–89 % de. The thiolate can readily be cleaved from the rhenium complex by a methylation/chelate ring‐closure strategy. The stereochemistry of the entire reaction sequence was corroborated for each step by X‐ray crystallography.

Synthesis of novel random and block copolymers of tert-butyldimethylsilyl methacrylate and methyl methacrylate by RAFT polymerization

Hydrophobic-hydrolysable copolymers consisting of methyl methacrylate (MMA) and tert-butyldimethylsilyl methacrylate (TBDMSMA) have been synthesized for the first time by Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization technique using cumyl dithiobenzoate (CDB) and cyanoisopropyl dithiobenzoate (CPDB) as chain transfer agents (CTAs). The monomer reactivity ratios for TBDMSMA (r1=1.40±0.03) and MMA (r2=1.08±0.03) have been determined using a non-linear least-squares fitting method. Well-defined random copolymers PMMA-co-PTBDMSMA have been prepared. Then, the versatility of the RAFT process to synthesize silylated block copolymers with controlled molecular weights and low polydispersities has been demonstrated using two strategies: the synthesis of PMMA–SC(S)Ph or PTBDMSMA–SC(S)Ph as macro-chain transfer agent (macro-CTA) for use in a two step method or an one-pot method which consists in the successive addition of the two monomers. Diblock copolymers with narrow molecular weight distributions (PDI<1.2) were obtained from the one-pot method with number-average molecular weight values within the range 10,000–22,000gmol−1.

The molecular and solid state structure of lead thiobenzoate Pb[SC(O)Ph] 2

The crystal and molecular structure of lead thiobenzoate Pb[SC(O)Ph] 2 has been determined by single crystal X-ray diffraction analysis. The thiobenzoate ligands are coordinated to the lead atom through the sulfur atoms of the thiobenzoate ligands. There are weak interactions with the oxygen atoms. In the solid state the structure exhibits a complex three dimensional network of Pb[SC(O)Ph] 2 units formed by bridging interactions by the sulfur atoms.

Preparation of Thiocarboxylate, Thiocarbamate and Xanthate Complexes of Pentacoordinate Nickel(II): Insertion of Heterocumulenes Into Nickel(II) Hydroxido Complexes

AbstractThe hydroxido complexes [Ni(N3‐mc)(μ‐OH)]2[PF6]2 [N3‐mc = 2,4,4‐trimethyl‐1,5,9‐triazacyclododec‐1‐ene (N3‐mc1) or 2,4,4,9‐tetramethyl‐1,5,9‐triazacyclododec‐1‐ene (N3‐mc2)] react in the presence of alcohols with CS2 or PhNCS to yield xanthate [(N3‐mc)Ni{S2C(OR′)}][PF6] or O‐alkyl N‐phenylthiocarbamate [(N3‐mc)Ni{PhNC(OR′)S}][PF6] complexes; these compounds represent the first examples of N,S‐chelating thiocarbamates bound to nickel(II). The reactions of [Ni(N3‐mc)(μ‐OH)]2[PF6]2 with thiocarboxylic acids yield the corresponding thiocarboxylate derivatives [(N3‐mc)Ni{SC(O)R′}][PF6]. These paramagnetic nickel(II) complexes were characterized by both one‐ and two‐dimensional (COSY) 1H NMR spectroscopic techniques. The crystal structures of [(N3‐mc2)Ni(S2COCH3)][PF6] (2), [(N3mc2)Ni{PhNC(OCH2CH3)S}][PF6] (8), [(N3‐mc2)Ni{SC(O)CH3}][PF6] (10) and [(N3‐mc1)Ni{SC(O)Ph}][PF6] (11) were determined. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2007)

One‐Pot Synthesis of Micelles with a Cross‐Linked Poly(acrylic acid) Core

AbstractSummary: Stable micelles with polystyrene (PS) as a shell and cross‐linked poly[(acrylic acid)‐co‐(ethylene glycol diacrylate)] as a core have been successfully prepared by reversible addition fragmentation chain transfer (RAFT) copolymerization of acrylic acid and ethylene glycol diacrylate in a selective solvent with PS‐SC(S)Ph as a RAFT agent. For the preparation of stable micelles, the RAFT polymerizations are carried out in different solvents: benzene, cyclohexane, and mixtures of tetrahydrofuran and cyclohexane. The monomer/PS‐SC(S)Ph molar ratio and molecular weight of the macro‐RAFT agent, PS‐SC(S)Ph, influence the RAFT polymerization and the formation of micelles.Block copolymerization in selective solvent with the RAFT agent.magnified imageBlock copolymerization in selective solvent with the RAFT agent.

Reversible Addition−Fragmentation Transfer Polymerization in Nanosized Micelles Formed in Situ

The reversible addition−fragmentation transfer (RAFT) polymerizations of 4-vinylpyridine (4VP) in tetrahydrofuran (THF) and in cyclohexane with RAFT agent, dithiobenzoate-terminated polystyrene (PS−SC(S)Ph), involve one polymerization rate (Rp = 0.083 mol L-1 h-1) and two stages of polymerization (Rp = 0.164 and 0.0024 mol L-1 h-1 before and after 5 h), respectively. The polymerization of 4VP and divinylbenzene (less than 10% relative to 4VP) in THF led to gelation, but the polymerization in cyclohexane displayed clear solution consistently throughout polymerization, and kinetic studies showed sudden decrease of polymerization rate and sharp increase of molecular weight at around 5 h. Polymerization was followed by gel permeation chromatography (GPC) and the combination of GPC and multiangle laser light scattering (MALLS). The results show the formation of micelles with PS as shell and poly(PVP-co-DVB) as core by microphase separation; the micelles' size increased fast around 5 h polymerization, and then ...

Synthesis of comb-shaped copolymers by combination of reversible addition–fragmentation chain transfer polymerization and cationic ring-opening polymerization

Comb-shaped graft copolymers with poly(methyl acrylate) as a handle were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization and ring-opening polymerization (ROP) techniques in three steps. First, copolymers of poly(styrene-co-chloromethyl styrene), poly(St- co-CMS), were prepared by RAFT copolymerization of St and CMS using 1-(ethoxycarbonyl)prop-1-yl dithiobenzoate (EPDTB) as RAFT agent. Second, the polymerization of MA using poly(St- co-CMS)-SC(S)Ph as macromolecular chain transfer agent produced block copolymer poly(St- co-CMS)- b-PMA. Third, cationic ring-opening polymerization of THF was performed using poly(St- co-CMS)- b-PMA/AgClO 4 as initiating system to produce comb-shaped copolymers. The structures of the poly(St- co-CMS), poly(St- co-CMS)- b-PMA and final comb-shaped copolymers were characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC).

Synthesis of hydrophilic/CO2‐philic poly(ethylene oxide)‐b‐poly(1,1,2,2‐tetrahydroperfluorodecyl acrylate) block copolymers via controlled/living radical polymerizations and their properties in liquid and supercritical CO2

AbstractHydrophilic/CO2‐philic poly(ethylene oxide)‐b‐poly(1,1,2,2‐tetrahydroperfluorodecyl acrylate) block copolymers were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization, iodine transfer polymerization (ITP), and atom transfer radical polymerization (ATRP) in the presence of either degenerative transfer agents or a macroinitiator based on poly(ethylene oxide). In this work, both RAFT and ATRP showed higher efficiency than ITP for the preparation of the expected copolymers. More detailed research was carried out on RAFT, and the living character of the polymerization was confirmed by an ultraviolet (UV) analysis of the SC(S)Ph or SC(S)SC12H25 end groups in the polymer chains. The quantitative UV analysis of the copolymers indicated a number‐average molecular weight in good agreement with the value determined by 1H NMR analysis. The properties of the macromolecular surfactants were investigated through the determination of the cloud points in neat liquid and supercritical CO2 and through the formation of water‐in‐CO2 emulsions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2405–2415, 2004

Thiocarbonylthio Compounds [SC(Ph)S−R] in Free Radical Polymerization with Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization). Role of the Free-Radical Leaving Group (R)

Radical polymerization with reversible addition−fragmentation chain transfer (RAFT polymerization) can be used to synthesize a wide range of polymers of controlled architecture and narrow molecular weight distribution. The polymerizations use addition−fragmentation chain transfer agents (RAFT agents) that possess high transfer coefficients in free radical polymerization and confer living character on the polymerization. This paper explores the effect of the substituents R of dithiobenzoate RAFT agents [SC(Ph)S−R] on the outcome of polymerizations of styrene, methyl methacrylate (MMA) and butyl (BA) or methyl acrylate (MA). In MMA polymerization at 60 °C, effectiveness depends strongly on R decreasing in the order where R is: −C(Alkyl)2CN ∼ −C(Me)2Ar > −C(Me)2C(O)O(alkyl) > −C(Me)2C(O)NH(alkyl) > −C(Me)2CH2C(Me)3 ≥ −C(Me)HPh > −C(Me)3 ∼ −CH2Ph. Of these, only the compounds with R = −C(Me)2Ph and −C(Me)2CN provided polymers with substantially narrowed polydispersities in batch polymerization and gave molec...

Heterogeneous reaction route to CuInS2 thin films

High quality thin films of CuInS2 have been deposited on a copper coated silicon substrate using vapors obtained from (Et3NH)[In(SC(O)Ph)4].

Monomeric, dimeric and polymeric [Cp 2MoH 2] complexes with AgS bonds

The reaction of [Cp 2MoH 2] and AgBF 4 with the dithio ligands Na(S 2CPh) and K(S 2CO i Pr) afforded the complexes [(Cp 2MoH 2AgS 2CPh) 2] ( 1) and [(Cp 2MoH 2AgS 2CO i Pr) 2] ( 2). Using the monothio ligands Na(SC(O)Ph), K(SC(O)CH 3) and Na(S(NHPh)CC(CN) 2) the complexes [(Cp 2MoH 2AgSC(O)Ph) 2] ( 3), [((Cp 2MoH 2) 2(AgSC(O)CH 3) 3) n ] ( 4) and [(Cp 2MoH 2) 2AgS(NHPh)CC(CN) 2] ( 6) were formed. The reaction of thiobenzamide and [(Cp 2MoH 2) 2AgCl] gave the complex [(Cp 2MoH 2Ag(Cl)S(NH 2)CPh) 2] ( 5). Complexes 1 and 2 have a dimeric structure with the two dithio ligands bridging the two silver atoms. Complex 3 is also a dimer, however, the monothio ligands are coordinated with their single sulphur atoms to the silver atoms. In the polymer 4 the thioacetate ligand has the same bonding mode as in 3. The three-dimensional structure of 4 is built-up of parallel strings. In the dimer 5 the thiobenzamide ligands bind with the sulphur atom to a silver atom each. Complex 6 has a monomeric structure in which the silver atom is coordinated to two [Cp 2MoH 2] ligands and to the sulphur atom of the S(NHPh)CC(CN) 2 ligand. Compounds 1– 6 were characterised analytically and spectroscopically and the structures were determined by single crystal X-ray analyses.

Synthesis, characterization, and reactivity of scandium chloro, alkyl, aryl, and borohydride complexes, Sc(η5-C5H5)R[N(SiMe2CH2PiPr2)2] (R = Cl, Me, Ph, and BH4)

Reaction of ScCl2(THF)[N(SiMe2CH2PiPr2)2] with NaCp(DME) leads to Sc(η5-C5H5)Cl[N(SiMe2CH2PiPr2)2] (1). The X-ray crystal structure shows the scandium centre to reside in a square pyramidal environment with the [N(SiMe2CH2PiPr2)2] - ligand bound in a pseudo-meridional fashion. The 1H NMR spectrum is consistent with a Cs symmetric structure in solution. Metathesis of the chloride ligand with RLi (R = Me, Ph, BH4) yields the five-coordinate species Sc(η5-C5H5)R[N(SiMe2CH2PiPr2)2]. Phenyl 3 and borohydride 4 are isolated as crystalline solids, while methyl 2 resisted crystallization. 2-4 exhibit 1H NMR spectra consistent with Cs symmetric solution structures. Sc(η5-C5H5)Ph[N(SiMe2CH2PiPr2)2] (3) was characterized in the solid state and found to have a similar geometry to that of the parent chloride. Reaction of Sc(η5-C5H5)Me[N(SiMe2CH2PiPr2)2] (2) with NH2R (R = Ph, tBu) yields the amides Sc(η5-C5H5)NHPh[N(SiMe2CH2PiPr2)2] (5) and Sc(η5-C5H5)NHtBu [N(SiMe2CH2PiPr2)2] (6) via σ-bond metathesis routes; these reactions are accompanied by a competing reaction at the scandium-amide bond to produce the protonated ligand, HN(SiMe2CH2PiPr2)2. 5 and 6 are also produced by salt-elimination from the chloride 1 and LiNHR (R = Ph, tBu). Sc(η5-C5H5)(BH4)[N(SiMe2CH2PiPr2)2] (4) reacts with PMe3 to produce the putative hydride, Sc(η5-C5H5)H[N(SiMe2CH2PiPr2)2] (7); this species was identified in solution. An equilibrium between 4, PMe3, 7, and PMe3·BH3 exists which greatly favors the starting scandium-borohydride. Crystals of Sc(η5-C5H5)Cl[N(SiMe2CH2PiPr2)2] (1) are monoclinic, a = 17.409(2), b = 10.0803(7), c = 17.688(2) Å, β = 94.606(8)°, Z = 4, space group P21/c; and those of Sc(η5-C5H5)Ph[N(SiMe2CH2PiPr2)2] (3) are triclinic, a = 10.5129(15), b = 19.124(2), c = 9.114(2) Å, α = 95.582(13), β = 107.047(12), γ = 90.042(11)°, Z = 2, space group P. The structures were solved by Patterson (1) and direct (3) methods and refined by full-matrix least-squares procedures to R = 0.047 and 0.054 (Rw = 0.042 and 0.049) for 2414 and 2844 reflections with I [Formula: see text] 3σ(I), respectively.Key words: scandium, σ-bond metathesis, borohydride.

Synthesis, structure, and multi-NMR studies of (Me4N)[A(M(SC(O)Ph)3)2] (A = Na, M = Hg; A = K, M = Cd or Hg).

The compounds (Me4N)[A(M(SC(O)Ph)3)2] (A = K, M = Cd (2); A = Na, M = Hg (3); and A = K, M = Hg (4)) were synthesized by reacting the appropriate metal chloride with A+PhC(O)S- and Me4NCl in the ratios 1:3:1 and 2:6:1. The structures of these compounds were determined by single-crystal X-ray diffraction methods. All the compounds are isomorphous, isostructural, and crystallized in the space group P1 with Z = 1. Single-crystal data for 2: a = 106670(2) A, b = 111522(2) A, c = 119294(2) A, alpha = 71782(1) degrees, beta = 85208(1) degrees, gamma = 69418(1) degrees, V = 126140(4) A3, Dcalc = 1528 g cm-3. Single-crystal data for 3: a = 10840(2) A, b = 10946(4) A, c = 12006(3) A, alpha = 7218(2) degrees, beta = 8675(2) degrees, gamma = 6743(2) degrees, V = 12493(6) A3, Dcalc = 1756 g cm-3. Single-crystal data for 4: a = 104780(1) A, b = 112563(2) A, c = 119827(2) A, alpha = 71574(1) degrees, beta = 85084(1) degrees, gamma = 70705(1) degrees, V = 126523(3) A3, Dcalc = 1755 g cm-3. In the [A(M(SC(O)Ph)3)2]- anions, each M(II) atom is bonded to three thiobenzoate ligands through sulfur atoms, giving a trigonal planar MS3 geometry. The carbonyl oxygen atoms from the two [M(SC(O)Ph)3]- anions are bonded to the alkali metal atom, providing an octahedral environment. Solution metal NMR studies showed the concentration-dependent dissociation of the alkali metal ions in the trinuclear anions.

Crystal and molecular structure of cis-bis(monothiodibenzoylmethanato)-dioxomolybdenum(VI)

Abstract The crystal and molecular structure of cis-bis(monothiodibenzoylmethanato)dioxomolybdenum(VI), [MoO2(SC(Ph)CHC(Ph)O)2], C30H22MoO4S2, has been determined at room temperature. The orange crystals are monoclinic, space group P21/n with unit cell dimensions a = 11.573(2) Å, b= 12.073(8) Å, c = 18.958(2) Å, β = 104.05(1)°, Z = 4 and D x = 1.568 Mg m−3. The structure was refined by a full-matrix least-squares procedure on F to final R = 0.045 using 2968 reflections with I ≥ 3.0σ(I). The Mo atom exists in a distorted octahedral geometry defined by a O4S2 donor set which features a cis-Mo(=O)2 and a trans-MoS2 arrangement. The coordination geometry is compared with related species.