Strontium Compound Research Articles

The Divalent Lanthanoid Triflates Ln(CF3SO3)2(CH3CN) (Ln=Sm, Eu): Structure, Luminescence, and Magnetism.

The reaction of the trivalent lanthanoide triflates Ln(OTf)3 (Ln=Sm, Eu; OTf=CF3SO3 -) with the respective metals in acetonitrile leads to the Ln(II)-triflates Eu(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1053.54(1), b=610.28(5), c=1946.92(2) pm, β =98.611(4)) and Sm(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1054.41(4), b=612.16(2), c=1952.65(7) pm, β =98.524(2)). The isotypic strontium compound Sr(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1056.39(5), b=610.05(3), c=1950.1(1) pm, β =98.900(2)°) has been obtained from SrCO3 and triflic acid. The compounds have been investigated by X-ray diffraction, vibrational spectroscopy, luminescence spectroscopy, cyclic voltammetry, thermal analysis, and magnetic measurements.

Study on the Growth and Regulation of Large-Particle Sr(OH)2·8H2O Crystals with Process Analytical Technology

Sr(OH)2 is an indispensable strontium compound extensively harnessed in sugar refining, strontium lubricating wax formulation, and polymer plastic stabilization. Sr(OH)2·8H2O is the prevalent hydrate form of Sr(OH)2. Deprived of moisture via vacuum drying, Sr(OH)2 can be procured from Sr(OH)2·8H2O. Sr(OH)2·8H2O particles with larger sizes exhibit impressive attributes such as facile solid–liquid divergence, elevated product purity, expedient drying, and resilience to agglomeration, which have garnered significant interest. Given the superior quality of the product and the dependability of the process, process analytical technology (PAT) has been extensively employed in the pharmaceutical sector, rendering it feasible to employ PAT to fabricate large-particle Sr(OH)2·8H2O crystals. This study utilizes industrial SrCO3 to prepare high-purity Sr(OH)2·8H2O with a purity of over 99.5%. The growth process of single crystals was observed using a hot-stage microscope, and the growth process of large-particle Sr(OH)2·8H2O was optimized and regulated online using PAT. The optimal process conditions were optimized, and large-particle Sr(OH)2·8H2O crystals were obtained by adding crystal seeds. On this basis, we proposed a seed control mechanism for Sr(OH)2·8H2O.

Ternary magnesium gallides – synthesis, crystal chemistry and properties of CaMgGa, SrMgGa, BaMgGa and YbMgGa

AbstractThe gallides CaMgGa, SrMgGa, BaMgGa and YbMgGa were synthesized from the elements in sealed tantalum ampoules in muffle furnaces. The phase purity of the samples was checked by powder X‐ray diffraction. CaMgGa and YbMgGa crystallize with the ZrNiAl type structure, space group P 2m, whereas SrMgGa and BaMgGa adopt an ordering variant of the Cu2Sb/PbFCl type, space group P4/nmm. The structures of SrMg0.884(7)Ga1.116(7) (a=459.23(9), c=792.43(12) pm, wR2=0.0371, 226 F2 values, 11 variables) and YbMgGa (a=774.55(7), c=411.95(4) pm, wR2=0.0329, 342 F2 values, 15 variables) were refined from single crystal X‐ray diffractometer data. Refinement of the occupancy parameters indicated a small degree of Mg/Ga mixing on the 2a site for the strontium compound. The [MgGa] substructures in both compounds are composed of condensed Mg@Ga4 tetrahedra with 4×287 pm Mg−Ga in SrMg0.884Ga1.116 vs 2×282 and 2×296 pm in YbMgGa. The SrMgGa structure has a stacking of layers of edge‐sharing Mg@Ga4 and Sr4 tetrahedra. Electronic structure calculations indicate a net charge transfer from strontium and magnesium to gallium. YbMgGa completes the series of REMgGa gallides. Temperature dependent magnetic susceptibility studies reveal weak Pauli paramagnetism, confirming divalent ytterbium.

Magnesium intermetallics: synthesis and structure of Eu2Pt2Mg and Sr2Pt2Mg

AbstractThe intermetallic phases Sr2Pt2Mg and Eu2Pt2Mg were obtained by reaction of the elements in sealed tantalum tubes at high temperature. Sr2Pt2Mg crystallizes with the monoclinic Ca2Ir2Si type (C2/c,a = 1020.7(7),b = 597.7(4),c = 827.0(4) pm,β = 103.37(5)°), while Eu2Pt2Mg adopts the orthorhombic W2CoB2-type structure (Immm,a = 440.31(5),b = 582.20(6),c = 914.11(9) pm,wR = 0.0359, 277F2values, 14 variables). The magnesium atoms in both structures are coordinated by four Pt2dumb-bells with a rectangular planar coordination in Eu2Pt2Mg (268 pm Pt–Mg) and a distorted tetrahedral one in Sr2Pt2Mg (273–275 pm Pt–Mg). The Pt–Pt distances are 277 pm in the europium and 269 pm in the strontium compound. The polyanionic [Pt2Mg] units are planar in Eu2Pt2Mg and separated by the europium atoms. The Sr2Pt2Mg structure shows the motif of hexagonal rod packing for the [Pt2Mg] rows that are embedded in a strontium matrix. Chemical bonding and the influence of the valence electron count on the formation of the structure types are discussed.

Synthesis and Characterization of Strontium N,N-Dimethylaminodiboranates as Possible Chemical Vapor Deposition Precursors.

The reaction of SrBr2 with 2 equiv of sodium N,N-dimethylaminodiboranate (DMADB; Na(H3BNMe2BH3)) in Et2O at 0 °C followed by crystallization and drying under vacuum gives the unsolvated strontium compound Sr(H3BNMe2BH3)2 (1). Before the vacuum-drying step, the colorless crystals obtained by crystallization consist of the diethyl ether adduct Sr(H3BNMe2BH3)2(Et2O)2 (2). If the reaction of SrBr2 with 2 equiv of Na(H3BNMe2BH3) is carried out in the more strongly coordinating solvent thf, the solvate Sr(H3BNMe2BH3)2(thf)3 (3) is obtained. Treating the thf adduct 3 with 1,2-dimethoxyethane (dme), bis(2-methoxyethyl) ether (diglyme), or N,N,N',N'-tetramethylethylenediamine (tmeda) in thf affords the new compounds Sr(H3BNMe2BH3)2(dme)2 (4), Sr(H3BNMe2BH3)2(diglyme) (5), and Sr(H3BNMe2BH3)2(tmeda) (6), respectively, in greater than 60% yields. Treatment of 3 with 2 equiv of the crown ether 12-crown-4 affords the charge-separated salt [Sr(H3BNMe2BH3)(12-crown-4)2][H3BNMe2BH3] (7). Crystal structures of all the Lewis base adducts are described. Compounds 2-6 all possess chelating κ2-BH3NMe2BH3-κ2 groups, in which two hydrogen atoms on each boron center are bound to strontium. Compound 6 is dinuclear because each metal atom is also coordinated to one hydrogen atom on a BH3NMe2BH3- ligand that chelates to the neighboring metal center. Compound 7 possesses an unusual κ1-BH3NMe2BH3- group owing to the near-complete encapsulation of the Sr atom by two 12-crown-4 molecules; the other BH3NMe2BH3- anion is a charge-separated counterion. When they are heated, the diglyme and tmeda compounds 5 and 6 melt without decomposition and can be sublimed readily under reduced pressure (1 Torr) at 120 °C. The diglyme and tmeda adducts are some of the most volatile strontium compounds known and are promising candidates as CVD precursors for the growth of strontium-containing thin films.

Oral Administration of Strontium Gluconate Effectively Reduces Articular Cartilage Degeneration Through Enhanced Anabolic Activity of Chondrocytes and Chondrogenetic Differentiation of Mesenchymal Stromal Cells.

Osteoarthritis (OA), a common degenerative disease affecting articular cartilage, is caused by multiple factors, and currently, there are few approaches to effectively delay its progression. This study aimed to evaluate whether a strontium compound (in the form of strontium gluconate, Glu-Sr) could reduce OA pathology severity in osteoarthritic rat models by directly targeting chondrocytes, including catabolic/anabolic activities and/or chondrogenic differentiation. Glu-Sr was administered to OA rats by oral gavage beginning during OA induction and continuing for 8weeks. Glu-Sr treatment was found to significantly reduce cartilage degeneration and delay OA progression. Further examination showed that collagen II, Sox9, and aggrecan (ACAN) genes were up-regulated whereas IL-1β was down-regulated in chondrocytes isolated from Glu-Sr-treated rats. Glu-Sr also antagonized the catabolic effects of IL-1β on chondrocytes. Furthermore, Glu-Sr was shown to promote the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs), possibly through promoting chondrogenic gene expression, including CTGF and FGF1, as revealed by RNA-sequencing (RNA-seq). These results suggest that systemic administration of Glu-Sr may be useful in prophylactic and therapeutic treatment of chronic cartilage degradation through affecting multiple steps from chondrogenic differentiation of progenitors to matrix formation in mature chondrocytes.

The synthesis and structure of the strontium complex with anthranilic acid and triethanolamine

In the framework of the systematic studies of the mixed ligand complexes formation on the base of ethanolamines and aromatic carboxylic acids new strontium compound with triethanolamine and anthranilic acid has been synthesized The structure of the obtained complex is determined by X ray crystallography In complex two triethanolamine molecules are tetradentantly coordinated by the central atom while two molecules of anthranilic acid in the benzoate form are located in the outer sphere

Origins of n -type doping difficulties in perovskite stannates

Materials that are simultaneously transparent and electrically conductive play a key role in optoelectronic devices. Barium stannate has recently come to the forefront as a promising new transparent conductor, but its conductivity has been difficult to control. The authors have performed computational studies to determine the mechanisms that limit doping. They find that atomic-scale defects, such as vacancies in the crystal lattice, are responsible, but their formation can be controlled by tailoring the growth conditions. The authors also investigated related materials, such as strontium stannate and calcium stannate, which are transparent even in the ultraviolet. Calcium stannate is found to always be insulating, but guidelines are provided for maximizing the conductivity of the strontium compound.

ChemInform Abstract: Group 2 Catalysis for the Atom‐Efficient Synthesis of Imidazolidine and Thiazolidine Derivatives.

AbstractAmong 3 alkaline earth bis(amide) precatalysts tested (M: Sr, Mg, Ca), the strontium compound is the most effective one.

Synthesis, crystal structure and thermal behavior of a new 1D polymeric strontium complex with tetrazole-1-acetic acid

A new 1D polymeric strontium compound (Sr(tza)2(H2O)2)n was synthesized by reaction of tetrazole-1-acetic acid (Htza) with strontium carbonate, and characterized by X-ray single crystal diffraction, elemental analysis and IR spectroscopy. The central Sr(II) atom is coordinated by eight O atoms from 4 tza − ions and two water molecules. A zigzag chain along the c-axis is constructed by the tridentate tza − anion bridging two Sr(II) atoms. Differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses were applied to assess the thermal decomposition behav- ior. The kinetic parameters were obtained by non-isothermal reaction kinetics, and the Arrhenius equation can be expressed as lnk = 22.17-258.2 × 10 3 /RT. The critical temperature of thermal explosion values, �S / = , �H / = andG / = were obtained at 562 K as, −65.71 J mol −1 K −1 , 255.51 kJ mol −1 and 291.78 kJ mol −1 , respectively.

Intervention timing of strontium treatment on estrogen depletion-induced osteoporosis in rats: Bone microstructure and mechanics

To evaluate the effect of intervention timing of Sr treatment on trabecular bone microstructure and mechanics. Ninety female rats were randomly divided into three batches with three groups in each batch. Each group was divided according to the initiation timing of vehicle or strontium compound (SrC), which was at week 0 (early), 4 (mid-term) and 8 (late) after the ovariectomy, respectively. The treatment lasted for 12 weeks. The trabecular bone biomechanical properties, trabecular bone tissue mechanical properties, trabecular bone microstructure, and bone remodeling were analyzed with mechanical testing, nanoindentation, microCT, and histomorphometry, respectively. The osteoblast and osteoclast phenotypic genes were analyzed with real-time polymerase chain reaction (PCR). Early and mid-term Sr treatment significantly increased biomechanical properties of trabecular bone, which was associated with increased microarchitecture parameters, increased bone formation parameters and up-regulation of osteoblast-related gene expression. Late Sr treatment failed to exert a beneficial effect on any of those parameters. The beneficial effect of Sr was dependent on the intervention timing in ovariectomized rats.

(2,2′-Bipyridyl-κ2N,N′)bis(η5-pentamethylcyclopentadienyl)barium

In the title compound, [Ba(C10H15)2(C10H8N2)], the Ba—N distances are 2.798 (3) and 2.886 (3) Å, and the Cp ring centroid distances to Ba2+ are 2.7291 (7) and 2.7192 (9) Å. The angle between the N atoms in the bypyridine ligand and the metal ion is 56.80 (8)° and the N—C—C—N torsion angle in the bi­pyridine ligand is 1.7 (4)°. The bi­pyridine ligand is almost planar, the dihedral angle formed by the intersection of the planes defined by the pyridyl rings being 3.04 (19)°, and the angle between the plane defined by the Ba2+ ion and the two bipyridyl N atoms and the plane defined by the 12 atoms of the bi­pyridine ligand is 10.2 (3)°. The average Ba—N and Ba—centroid distances are 0.16 and 0.14 Å longer, respectively, than the equivalent distances in the isotypic strontium compound [Kazhdan et al. (2008 ▶). Acta Cryst. E64, m1134]. This difference is in accord with the difference between the ionic radii of 0.16 Å suggested by Shannon [Acta Cryst. (1976 ▶), A32, 751–767].

Accumulation of bone strontium measured by in vivo XRF in rats supplemented with strontium citrate and strontium ranelate

Strontium ranelate is an approved pharmacotherapy for osteoporosis in Europe and Australia, but not in Canada or the United States. Strontium citrate, an alternative strontium salt, however, is available for purchase over-the-counter as a nutritional supplement. The effects of strontium citrate on bone are largely unknown. The study's objectives were 1) to quantify bone strontium accumulation in female Sprague Dawley rats administered strontium citrate (N=7) and compare these levels to rats administered strontium ranelate (N=6) and vehicle (N=6) over 8weeks, and 2) to verify an in vivo X-ray fluorescence spectroscopy (XRF) system for measurement of bone strontium in the rat. Daily doses of strontium citrate and strontium ranelate were determined with the intention to achieve equivalent amounts of elemental strontium. However, post-hoc analyses of each strontium compound conducted using energy dispersive spectrometry microanalysis revealed a higher elemental strontium concentration in strontium citrate than strontium ranelate. Bone strontium levels were measured at baseline and 8weeks follow-up using a unique in vivo XRF technique previously used in humans. XRF measurements were validated against ex vivo measurements of bone strontium using inductively coupled plasma mass spectrometry. Weight gain in rats in all three groups was equivalent over the study duration. A two-way ANOVA was conducted to compare bone strontium levels amongst the three groups. Bone strontium levels in rats administered strontium citrate were significantly greater (p<0.05) than rats administered strontium ranelate and vehicle. ANCOVA analyses were performed with Sr dose as a covariate to account for differences in strontium dosing. The ANCOVA revealed differences in bone strontium levels between the strontium groups were not significant, but that bone strontium levels were still very significantly greater than vehicle.

Case of a Strong Antiferromagnetic Exchange Coupling Induced by Spin Polarization of a Mn–Mn Partial Single Bond

The large antiferromagnetic coupling in the Mn(IV)-Mn(IV) bond in the Li(6)Ca(2)[Mn(2)N(6)] and Li(6)Sr(2)[Mn(2)N(6)] crystals (J = -739 and -478 cm(-1), respectively, with H = -JS(A)·S(B)) is studied using different theoretical methods: solid-state density functional theory calculations, molecular density functional theory, and post-Hartree-Fock calculations with large embeddings. This magnetic coupling is a challenge for theoretical methods because both correlation and polarization effects are crucial for the correct description of the bond. All methods predict a large antiferromagnetic coupling, but none of the considered methods give a quantitative agreement with the experimental values. The molecular methods, except B3LYP and CASPT2, underestimate the coupling for the calcium compound, while they overestimate it in the strontium compound, within 30%. These methods, on the other hand, strongly underestimate the decrease of the coupling between the two compounds, with the most correlated one predicting the same value for both compounds. The solid-state method overestimates the coupling within 60% but reproduces better their ratio. Analysis of the calculations shows that the magnetic coupling between the local π orbitals is not caused by a direct interaction but by the spin-polarized σ bond.

Synthesis and pharmacokinetics of strontium fructose 1,6-diphosphate (Sr-FDP) as a potential anti-osteoporosis agent in intact and ovariectomized rats

A novel strontium compound has been synthesized by the reaction of fructose-1,6-diphosphate with strontium (Sr-FDP). The compound was characterized and confirmed with elemental analyses and spectroscopic (IR, NMR) methods. The pharmacokinetic profiles of Sr-FDP were investigated in Sprague–Dawley rats following oral administration at a dose of 110, 220, and 440 mg/kg respectively. Pharmacokinetic differences were also compared in intact rats and ovariectomized rats with and without estrogen supplement. Strontium concentrations in plasma, urine, tissue and feces were determined by graphite furnace atomic absorption spectroscopy (GFAAS). The results showed that Sr-FDP was absorbed rapidly with T max < 1 h in all the groups with AUC 0–∞ proportional to the oral dose. The pharmacokinetic profiles were characterized by long half-life , a large apparent volume of distribution. The highest Sr concentration was observed in the bone at 6 h, and the level of Sr decreased close to the baseline in heart, liver, spleen, lung, intestine, brain and kidney after 12 h. The cumulative amounts of Sr over 96 h were found to be ~ 3% in urine, but ~ 70% in feces suggesting that the parent drug was mainly excreted from the intestine. The C max and AUC 0–∞ of Sr-FDP in ovariectomized rats were significantly decreased compared to those in intact rats, and this trend was ameliorated by using 17-beta-estradiol (E 2) treatment in the ovariectomized rats.

Untersuchungen zu Reaktionen des Diphosphanylsilans iPr2Si(PH2)2 mit Erdalkalimetallsilazaniden

AbstractThe reaction of iPr2Si(PH2)2 (1) with [Ca{N(SiMe3)2}2(THF)2] at 25 °C in molar ratio 1:1 yields the compound [Ca3{iPr2Si(PH)2}3(THF)6] (2). Compound 2 consists of two Ca2P3 trigonal bipyramids with one conjoint calcium corner and SiiPr2 bridged phosphorus atoms. In contrast, the same reaction at 60 °C yield the complex [Ca({P(SiiPr2)2PH}2(THF)4] (3). The isotype strontium compound [Sr({P(SiiPr2)2PH}2(THF)4] (4) was obtained from the reaction of iPr2Si(PH2)2 with [Sr{N(SiMe3)2}2(DME)2]. The Compounds 2–4 were characterised by single crystal X‐ray diffraction, elemental analysis as well as IR and NMR spectroscopic techniques.

Aminotroponiminate calcium and strontium complexes

Heteroleptic aminotroponiminate complexes of calcium and strontium have been prepared. The monomeric calcium complex [((iPr)2ATI)CaI(THF)3] 1 ((iPr)2ATI = N-isopropyl-2-(isopropylamino)troponiminate) and the corresponding dimeric strontium compound [( (iPr)2ATI)SrI(THF)2]2 2 were obtained by reaction of [((iPr)2ATI)K] and MI2. Whereas the mixed ligand compound of composition [((iPr)2ATI)Ca(iPrAT)]2 3 (iPrAT = 2-(isopropylamino)troponate) was not obtained via a salt metathesis but by reaction of [Ca(N(SiMe3)2)2(THF)2] with ( (iPr)2ATI)H and (iPrAT)H, the diphosphanylamido complex [( (iPr)2ATI)Ca((Ph2P)2N)(THF)2] was obtained by reaction of CaI2 with the potassium compounds [( (iPr)2ATI)K] and [K(THF)n][N(PPh2)2]. The single crystal X-ray structures of all compounds were established and the latter compound shows a eta2-coordination mode of the ligand via the nitrogen and one phosphorus atom.

Influence of strontia on various properties of Surgical Simplex ® P acrylic bone cement and experimental variants

The fact that the composition of acrylic bone cement, as used in cemented primary arthroplasties, is not optimal has been highlighted in the literature. For example: (i) deleterious effects of the radiopacifier (BaSO 4 or ZrO 2 particles in the powder) have been reported; (ii) there is an indication that pre-polymerized poly(methylmethacrylate) (PMMA) beads in the powder may be dispensed with; and (iii) there is a strong consensus that the accelerator commonly used, N, N-dimethyl- p-toluidine (DMPT), is toxic and has many other undesirable properties. At the same time, the effectiveness of drugs that contain a strontium compound in treating the effects of osteoporosis has been explained in terms of the role of strontium in bone formation and resorption. This indicates that strontium compounds may also have desirable effects on osseointegration of arthroplasties. The present study is a detailed evaluation of 24 acrylic bone cement formulations comprising different relative amounts of BaSO 4, strontia (as an alternative radiopacifier), pre-polymerized PMMA beads and DMPT. A large number of properties of the curing and cured cement were determined, including setting time, polymerization rate, fracture toughness and fatigue life. The focus was on the radiopacifier, with the finding being that many properties of formulations that contained strontia were about the same or better than those for cements that contained BaSO 4. Thus, further developmental work on strontia-containing acrylic bone cements is justified, with a view to making them candidates for use in cemented primary arthroplasties.

Synthese und Struktur der basischen Erdalkalinitrate Sr2(OH)3NO3 und Ba2(OH)3NO3

AbstractSynthesis and Structure of the Basic Alkaline Earth Nitrates Sr2(OH)3NO3 and Ba2(OH)3NO3Sr2(OH)3NO3 and Ba2(OH)3NO3 were synthesized from mixtures of freshly prepared strontium or barium hydroxides and their corresponding nitrates in evacuated quartz glass ampoules at 420 °C and 360 °C, respectively. Single crystals of Sr2(OH)3NO3 were obtained in a solidified Sr(NO3)2 melt after subsequent heating and cooling cycles in air up to 600 °C. The crystal structure of the strontium compound was refined from single crystal and powder X‐ray data. Sr2(OH)3NO3 crystallizes hexagonally in the space group $\rm P{\bar 6}\rm 2m$ (No. 189) with Z = 1 and the lattice parameters a = 6.624(2) Å and c = 3.560(1) Å (single crystal data). The powder pattern of Ba2(OH)3NO3 was indexed isotypically to Sr2(OH)3NO3 with the lattice parameters a = 6.9260(1) Å and c = 3.8086(1) Å, and the crystal structure was refined from powder X‐ray data. Alkaline earth ions in the structures are surrounded trigonal‐prismatically by six hydroxide ions. These prisms are sharing their trigonal faces along [001] building up columns. These columns are connected in the ab‐plane by shared edges, and form hexagonal tunnels with the nitrate groups stacked inside. Infrared and thermoanalytical data of Sr2(OH)3NO3 are presented.

Good to the bone: Strontium compound prevents some fractures

Science NewsVolume 165, Issue 5 p. 68-68 This Week Good to the bone: Strontium compound prevents some fractures Nathan Seppa, Nathan SeppaSearch for more papers by this author Nathan Seppa, Nathan SeppaSearch for more papers by this author First published: 02 July 2009 https://doi.org/10.2307/4014992AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume165, Issue531 January 2004Pages 68-68 RelatedInformation