Swelling and biocompatibility of sodium alginate/poly(γ‐glutamic acid) hydrogels

Sodium alginate (Alg) hydrogel films were crosslinked with either calcium poly(γ‐glutamate) (Ca‐PGA) or CaCl₂. The hydrophilicity of the resulting hydrogel films was evaluated through swelling tests, water retention capacity tests, and water vapor permeation tests. The swelling ratio, water retention capacity, and the water vapor transmission rate (WVTR) of Alg/Ca‐PGA were higher than those of Ca‐Alg. The swelling ratio of Alg/Ca‐PGA was 651 and 190% at pH 7.4 and pH 1.2, respectively. The tensile strength of Alg/Ca‐PGA hydrogel was lower than that of Ca‐Alg. The results of hemocompatibility test showed that Alg/Ca‐PGA caused shorter activated partial thromboplastin time (APTT) than Ca‐Alg. Both Ca‐Alg and Alg/Ca‐PGA exhibited almost no adsorption of human serum albumin (HSA), whereas the adsorption of human plasma fibrinogen (HPF) of Ca‐Alg was 10 times of that of Alg/Ca‐PGA. In addition, Alg/Ca‐PGA exhibited platelet adhesion higher than Ca‐Alg. Furthermore, both Alg/Ca‐PGA and Ca‐Alg exhibited no cytotoxicity. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of Temperature on Self‐Interaction of Human‐Like Collagen

Effects of temperature on self‐interaction of human‐like collagen (HLC) were investigated by hydrophobic interaction chromatography, calorimetric measurement, and sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis. Results show that three types of interaction roles may exist between HLC molecules at 3–50°C, which were divided into three narrower temperature ranges. In temperature range from 3–22°C, hydrogen bonding plays a key role in the formation of a gelatinous aggregate. In the range of 22–38°C, hydrophobic bonds accompanied by hydrogen bonds are involved in the formation compact aggregates. When temperature is above 38°C the hydrophobic effect formed in the HLC monomer results in the loss of its ability to self‐interact.     

Poly(γ‐glutamic acid)/Silica Hybrids with Calcium Incorporated in the Silica Network by Use of a Calcium Alkoxide Precursor

Current materials used for bone regeneration are usually bioactive ceramics or glasses. Although they bond to bone, they are brittle. There is a need for new materials that can combine bioactivity with toughness and controlled biodegradation. Sol‐gel hybrids have the potential to do this through their nanoscale interpenetrating networks (IPN) of inorganic and organic components. Poly(γ‐glutamic acid) (γ‐PGA) was introduced into the sol‐gel process to produce a hybrid of γ‐PGA and bioactive silica. Calcium is an important element for bone regeneration but calcium sources that are used traditionally in the sol‐gel process, such as Ca salts, do not allow Ca incorporation into the silicate network during low‐temperature processing. The hypothesis for this study was that using calcium methoxyethoxide (CME) as the Ca source would allow Ca incorporation into the silicate component of the hybrid at room temperature. The produced hybrids would have improved mechanical properties and controlled degradation compared with hybrids of calcium chloride (CaCl₂), in which the Ca is not incorporated into the silicate network. Class II hybrids, with covalent bonds between the inorganic and organic species, were synthesised by using organosilane. Calcium incorporation in both the organic and inorganic IPNs of the hybrid was improved when CME was used. This was clearly observed by using FTIR and solid‐state NMR spectroscopy, which showed ionic cross‐linking of γ‐PGA by Ca and a lower degree of condensation of the Si species compared with the hybrids made with CaCl₂ as the Ca source. The ionic cross‐linking of γ‐PGA by Ca resulted in excellent compressive strength and reduced elastic modulus as measured by compressive testing and nanoindentation, respectively. All hybrids showed bioactivity as hydroxyapatite (HA) was formed after immersion in simulated body fluid (SBF).     

A new layered Ca–succinate coordination polymer

A new layered Ca–succinate coordination polymer, poly[μ₃‐succinato‐calcium(II)], [Ca(C₄H₅O₄)]_n, was synthesized by reaction of CaCl₂·2H₂O and succinic acid in an aqueous medium under hydrothermal microwave conditions. The structure contains infinite layers of edge‐sharing calcium pentagonal–bipyramidal polyhedra forming six‐membered rings connected through succinate ligands. Such an assembly of inorganic building units is unique for calcium metal–organic framework‐type structures. Adjacent layers are packed into a final pseudo‐three‐dimensional structure through weak C—H...O hydrogen bonds.     

Calcium Hydroxide Chlorides: The Ternary System Ca(OH)2‐CaCl2‐H2O at 25, 40, and 60 °C,Phase Stoichiometry and Crystal Structure

The formation of calcium hydroxide chlorides is an important issue in processes of the chemical raw materials industry, in terms of purification of flue gases, and concrete/cement corrosion. Current information on phase compositions given in the literature are contradictory. In this work systematic solubility studies were carried out at 25, 40, and 60 °C in the system Ca(OH)₂‐CaCl₂‐H₂O and the compositions of the ternary solid phases were precisely determined using the Schreinemakers' method. Two ternary phases were identified, the hydrate 3Ca(OH)₂ · CaCl₂ · 12H₂O and the anhydrous calcium hydroxide chloride Ca(OH)₂ · CaCl₂. The crystal structure of 3Ca(OH)₂ · CaCl₂ · 12H₂O was solved by means of single‐crystal X‐ray diffraction at –123 °C (150 K).     

Calcium Hydride Catalyzed Highly 1,2‐Selective Pyridine Hydrosilylation

Reaction of the calcium hydride complex (DIPPnacnac‐CaH?THF)₂ with pyridine is much faster and selective than that of the corresponding magnesium hydride complex (DIPPnacnac = [(2,6‐iPr₂C₆H₃)NC(Me)]₂CH). With a range of pyridine, picoline and quinoline substrates, exclusive transfer of the hydride ligand to the 2‐position is observed and also at higher temperatures no 1,2→1,4 isomerization is found. The heteroleptic product DIPPnacnac‐Ca(1,2‐dihydropyridide)?(pyridine) shows fast ligand exchange into homoleptic calcium complexes and therefore could not be isolated. Calcium hydride reduction of isoquinoline gave well‐defined homoleptic products which could be characterized by X‐ray diffraction: Ca(1,2‐dihydroisoquinolide)₂?(isoquinoline)₄ and Ca₃(1,2‐dihydroisoquinolide)₆?(isoquinoline)₆. The striking selectivity difference in the dearomatization of pyridines by Mg or Ca complexes could be explained by DFT theory and was utilized in catalysis. Whereas hydroboration of pyridine with pinacol borane with a calcium hydride catalyst gave only minor conversion, the hydrosilylation of pyridine and quinolines with PhSiH₃ yields exclusively 1,2‐dihydropyridine and 1,2‐dihydroquinoline silanes with 80–90 % conversion. Similar results can be achieved with the catalyst Ca[N(SiMe₃)₂]₂?(THF)₂. These calcium complexes represent the first catalysts for the 1,2‐selective hydrosilylation of pyridines.     

Chiral Calcium–BINOL Phosphate Catalyzed Diastereo‐ and Enantioselective Synthesis of syn‐1,2‐Disubstituted 1,2‐Diamines: Scope and Mechanistic Studies

A highly enantioselective, chiral, Lewis acid calcium–bis(phosphate) complex, Ca[ 3 a ]_n, which catalyzes the electrophilic amination of enamides with azodicarboxylate derivatives 2 to provide versatile chiral 1,2‐hydrazinoimines 4 is disclosed. The reaction gives an easy entry to optically active syn‐1,2‐disubstituted 1,2‐diamines 6 in high yields with excellent enantioselectivities, after a one‐pot reduction of the intermediate 1,2‐hydrazinoimines 4 . The geometry and nature of the N‐substituent of the enamide affect dramatically both the reactivity and the enantioselectivity. Although the calcium–bis(phosphate) complex was a uniquely effective catalyst, the exact nature of the active catalytic species remains unclear. NMR spectroscopy and MS analysis of the various calcium complexes Ca[ 3 ]_n reveals that the catalysts exist in various oligomer forms. The present mechanistic study, which includes nonlinear effects and kinetic measurements, constitutes a first step in understanding these calcium–bis(phosphate) complex catalysts. DFT calculations were carried out to explore the mechanism and the origin of the enantioselectivity with the Ca[ 3 ]_n catalysts.     

Solvation of Calcium–Phosphate Headgroup Complexes at the DPPC/Aqueous Interface

The effects of sodium (Na⁺) and calcium (Ca²⁺) cations on model zwitterionic dipalmitoylphosphatidylcholine (DPPC) monolayers spread on metal chloride salt solutions are investigated by means of vibrational sum frequency generation (VSFG) and heterodyne‐detected (HD)‐VSFG spectroscopy. VSFG and HD‐VSFG spectra in the OH stretching region reveal cation‐specific effects on the interfacial water′s H‐bonding network, knowledge of which has been limited to date. It is found that low‐concentrated Ca²⁺ more strongly perturbs interfacial water organization relative to highly concentrated Na⁺. At higher Ca²⁺ concentrations, the water H‐bonding network at the DPPC/CaCl₂ interface reorganizes and the resulting spectrum closely follows that of the bare air/CaCl₂ interface up to ～3400 cm^?1. Most interesting is the appearance of a negative band at ～3450 cm^?1 in the DPPC/CaCl₂ Im χ_s⁽²⁾ spectra, likely arising from an asymmetric solvation of Ca²⁺–phosphate headgroup complexes. This gives rise to an electric field that orients the net OH transition moments of a subset of OH dipoles toward the bulk solution.     

Calcium–Amidoborane–Ammine Complexes: Thermal Decomposition of Model Systems

Hydrocarbon‐soluble model systems for the calcium–amidoborane–ammine complex Ca(NH₂BH₃)₂ ? (NH₃)₂ were prepared and structurally characterized. The following complexes were obtained by the reaction of RNH₂BH₃ (R=H, Me, iPr, DIPP; DIPP=2,6‐diisopropylphenyl) with Ca(DIPP‐nacnac)(NH₂) ? (NH₃)₂ (DIPP‐nacnac=DIPP? NC(Me)CHC(Me)N? DIPP): Ca(DIPP‐nacnac)(NH₂BH₃) ? (NH₃)₂, Ca(DIPP‐nacnac)(NH₂BH₃) ? (NH₃)₃, Ca(DIPP‐nacnac)[NH(Me)BH₃] ? (NH₃)₂, Ca(DIPP‐nacnac)[NH(iPr)BH₃] ? (NH₃)₂, and Ca(DIPP‐nacnac)[NH(DIPP)BH₃] ? NH₃. The crystal structure of Ca(DIPP‐nacnac)(NH₂BH₃) ? (NH₃)₃ showed a NH₂BH₃^? unit that was fully embedded in a network of BH???HN interactions (range: 1.97(4)–2.39(4) Å) that were mainly found between NH₃ ligands and BH₃ groups. In addition, there were N? H???C interactions between NH₃ ligands and the central carbon atom in the ligand. Solutions of these calcium–amidoborane–ammine complexes in benzene were heated stepwise to 60 °C and thermally decomposed. The following main conclusions can be drawn: 1) Competing protonation of the DIPP‐nacnac anion by NH₃ was observed; 2) The NH₃ ligands were bound loosely to the Ca²⁺ ions and were partially eliminated upon heating. Crystal structures of [Ca(DIPP‐nacnac)(NH₂BH₃) ? (NH₃)]_∞, Ca(DIPP‐nacnac)(NH₂BH₃) ? (NH₃) ? (THF), and [Ca(DIPP‐nacnac){NH(iPr)BH₃}]₂ were obtained. 3) Independent of the nature of the substituent R in NH(R)BH₃, the formation of H₂ was observed at around 50 °C. 4) In all cases, the complex [Ca(DIPP‐nacnac)(NH₂)]₂ was formed as a major product of thermal decomposition, and its dimeric nature was confirmed by single‐crystal analysis. We proposed that thermal decomposition of calcium–amidoborane–ammine complexes goes through an intermediate calcium–hydride–ammine complex which eliminates hydrogen and [Ca(DIPP‐nacnac)(NH₂)]₂. It is likely that the formation of metal amides is also an important reaction pathway for the decomposition of metal–amidoborane–ammine complexes in the solid state.     

Halide‐Free Diarylcalcium Complexes—Syntheses,Structures, and Stability

A general procedure was developed for the synthesis of diarylcalcium complexes by addition of KOtBu to arylcalcium iodides in THF. Intermediate arylcalcium tert‐butanolate dismutates immediately leading to insoluble tert‐butanolate precipitates of calcium. Depending on the steric demand and denticity of additional neutral aliphatic azabases, mononuclear or dinuclear complexes trans‐[Ca(α‐Naph)₂(thf)₄] ( 1 ), [Ca(β‐Naph)₂(thf)₄] ( 2 ), [Ca(Tol)₂(tmeda)]₂ ( 3 ), [Ca(Ph)₂(tmeda)]₂ ( 4 ), [Ca(Ph)₂(pmdta)(thf)] ( 5 ), [Ca(hmteta)(Ph)₂] ( 6 ), and [Ca([18]C‐6)(Ph)₂] ( 7 ) were isolated (Naph=naphthyl; meda=N,N,N′,N′‐tetramethylethylenediamine; pmdta= N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine; hmteta=N,N,N′,N′′,N′′′,N′′′‐hexamethyltriethylenetetramine). The Ca?C bond lengths vary between 250.8 and 263.5 pm, the ipso‐carbon atoms show low‐field‐shifted resonances in the ¹³C NMR spectra.     

Crystal structures of hydrates of simple inorganic salts. II. Water‐rich calcium bromide and iodide hydrates: CaBr2·9H2O,CaI2·8H2O,CaI2·7H2O and CaI2·6.5H2O

Single crystals of calcium bromide enneahydrate, CaBr₂·9H₂O, calcium iodide octahydrate, CaI₂·8H₂O, calcium iodide heptahydrate, CaI₂·7H₂O, and calcium iodide 6.5‐hydrate, CaI₂·6.5H₂O, were grown from their aqueous solutions at and below room temperature according to the solid–liquid phase diagram. The crystal structure of CaI₂·6.5H₂O was redetermined. All four structures are built up from distorted Ca(H₂O)₈ antiprisms. The antiprisms of the iodide hydrate structures are connected either via trigonal‐plane‐sharing or edge‐sharing, forming dimeric units. The antiprisms in calcium bromide enneahydrate are monomeric.     

Enantiopure Calcium Iminophosphonamide Complexes: Synthesis,Photoluminescence, and Catalysis

The synthesis of calcium complexes ligated by three different chiral iminophosphonamide ligands, L- H ( L =[Ph₂P{N(R)CH(CH₃)Ph}₂]), L′ -H ( L′ =[Ph₂P{NDipp}{N(R)CH(CH₃)Ph}]), (Dipp=2,6-ⁱPr₂C₆H₃), and L′′ -H ( L′′ =[Ph₂P{N(R)CH(CH₃)naph}₂]), (naph=naphthyl) is presented. The resulting structures [ L ₂Ca], [ L′ ₂Ca], and [ L′′ ₂Ca] represent the first examples of enantiopure homoleptic calcium complexes based on this type of ligands. The calcium complexes show blue–green photoluminescence (PL) in the solid state, which is especially bright at low temperatures. Whereas the emission of [ L′′ ₂Ca] is assigned to the fluorescence of naphthyl groups, the PL of [ L ₂Ca] and [ L′ ₂Ca] is contributed by long-lived phosphorescence and thermally activated delayed fluorescence (TADF), with a strong variation of the PL lifetimes over the temperature range of 5–295 K. Furthermore, an excellent catalytic activity was found for these complexes in hydroboration of ketones at room temperature, although no enantioselectivity was achieved.     

Selective Water Sorbents for Multiple Applications. 11. CaCl2 Confined to Expanded Vermiculite

This paper presents the water sorption properties of a new selective water sorbent based on expanded vermiculite as a host matrix and calcium chloride as a hygroscopic salt. Sorption isobars, isosters and isotherms at T = 30–150°C and vapor partial pressure 8.2–42.0 mbar clearly show that at low water contents crystalline hydrates with 0.33, 1 and 2 molecules of water per 1 molecule of CaCl₂ are formed in the pores. These hydrates are stable over a temperature change of 20–30°C and exhibit kinetically slow transformations. At higher water uptake, the vapor absorption leads to the formation of a CaCl₂ aqueous solution inside the pores, which properties are close to those in the bulk. Isosteric sorption heat was found to depend on water sorption and change from 76.3 kJ/mol for solid hydrates to 39.1–46.6 kJ/mol.     

One‐pot synthesis of polyamide 12,T–polyamide‐6 block copolymers

Polyamide 12,T–polyamide‐6 (PA‐12,T–PA‐6) block copolymers were synthesized by anionic polymerization of caprolactam using a PA‐12,T macrocoinitiator (McI). PA‐12,T McI and its precursors are soluble in molten caprolactam allowing for both the McI step‐growth polymerization and anionic polymerization to be performed in one‐pot. It was found that the competing reaction rates of caprolactam ring‐opening polymerization and McI transamidation are both deterred by a common ion effect using CaCl₂ and soluble materials were obtained using >1 mol % CaCl₂. Without CaCl₂, the reaction mixture solidifies in less than 30 s and produces crosslinked materials. To understand this effect, PA‐12,T McI reactions with caprolactam were performed with 1–10 mol % CaCl₂, and polymer structures were characterized using ¹³C NMR and dilute solution viscometry. These data were then correlated with unique thermal properties and swelling behavior of the block copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Formulation characterization and in vitro evaluation of acacia gum–calcium alginate beads for oral drug delivery systems

In the present work, new matrix bead formulations based on linear and branched polysaccharides have been developed using an ionic gelation technique, and their potential use as oral drug carriers has been evaluated. Using calcium chloride as a cross‐linking agent and sodium diclofenac (SD), as a model drug, acacia gum–calcium alginate matrix beads were formulated. The response surface methodology based on 3² factorial design was used as a statistical method to evaluate and optimize the effects of the biopolymers‐blend ratio and the concentration of calcium chloride on the particle size (mm), density (g/cm³), drug encapsulation efficiency (%), and the cumulative drug release after 8 hours (R_8h,%). The optimized beads with the highest drug encapsulation efficiency were examined for a drug‐excipients compatibility by powder X‐ray diffraction, differential scanning calorimetry, thermo‐gravimetric analysis, and Fourier transform‐infrared spectroscopy analyses. The swelling and degradation of the matrix beads were found to be influenced by the pH of medium. Higher degrees of swelling were observed in intestinal pH than in stomach pH. Accordingly, the drug release study showed that the amount of SD released from the acacia gum–calcium alginate beads was higher in intestinal pH than in stomach pH. Therefore, the in vitro drug release from the SD‐loaded beads appears to follow the controlled‐release (Hixson‐Crowell) pattern involving a case‐2 transport mechanism operated by swelling and relaxation of the polymeric blend matrix.     

Physico‐chemical study of sucrose and calcium ions interactions in alkaline aqueous solutions

Interactions between sucrose and calcium hydoxide have been the subject of our work. They were studied in dilute solutions (sucrose concentration <40% w/w, with a molar stoichiometric ratio Ca(OH)₂/sucrose <2) by several physico‐chemical methods, titration of free and bound calcium ions, ¹³C NMR spectroscopy, static light scattering and low shear viscosimetry. From these analyses we propose a polymer‐like complex formation with calcium ions bound to at least two sucrose molecules. Moreover, this polymer‐like aggregate can be described as a linear short chain at low Ca(OH)₂ and sucrose concentrations and as dense fractal particles at higher concentrations.     

钙磷物质的量比对磷酸钙骨水泥性能的影响

本研究通过在磷酸钙骨水泥(calcium phosphate cement,CPC)固相配方中添加不同量的氯化钙(CaCl2),制备不同钙磷物质的量比的CPC,研究不同钙磷物质的量比对CPC性能的影响。测试CPC的初、终凝时间。将CPC体外模拟浸泡3d和7d,研究模拟生理条件下CPC的性能,分别利用X-射线衍射(XRD)、力学性能实验机、扫描电镜(SEM)等研究CPC相成分、抗压强度和断面微观形貌。通过化学滴定测定浸泡液中氯离子浓度。结果表明:提高钙磷物质的量比不会显著延长CPC凝结时间;模拟浸泡液中的氯离子浓度处于正常生理条件的范围内;随钙磷物质的量比的增加,水化后CPC的抗压强度显著提高,而经过体外模拟浸泡后,钙磷物质的量比为1.67和1.80的CPC的抗压强度明显下降;具有较高钙磷物质的量比的CPC体外模拟浸泡后,形成多孔结构、弱结晶类骨磷灰石的终产物。     

Calcium-mediated dearomatization, C-H bond activation, and allylation of alkylated and benzannulated pyridine derivatives

A facile and general synthetic pathway for the production of dearomatized, allylated, and C? H bond activated pyridine derivatives is presented. Reaction of the corresponding derivative with the previously reported reagent bis(allyl)calcium, [Ca(C₃H₅)₂] ( 1 ), cleanly affords the product in high yield. The range of N‐heterocyclic compounds studied comprised 2‐picoline ( 2 ), 4‐picoline ( 3 ), 2,6‐lutidine ( 4 ), 4‐tert‐butylpyridine ( 5 ), 2,2′‐bipyridine ( 6 ), acridine ( 7 ), quinoline ( 8 ), and isoquinoline ( 9 ). Depending on the substitution pattern of the pyridine derivative, either carbometalation or C? H bond activation products are obtained. In the absence of methyl groups ortho or para to the nitrogen atom, carbometalation leads to dearomatized products. C(sp³)? H bond activation occurs at ortho and para situated methyl groups. Steric shielding of the 4‐position in pyridine yields the ring‐metalated product through C(sp²)? H bond activation instead. The isolated compounds [Ca(2‐CH₂‐C₅H₄N)₂(THF)] ( 2 b ?(THF)), [Ca(4‐CH₂‐C₅H₄N)₂(THF)₂] ( 3 b ?(THF)₂), [Ca(2‐CH₂‐C₅H₃N‐6‐CH₃)₂(THF)_n] ( 4 b ?(THF)_n; n=0, 0.75), [Ca{2‐C₅H₃N‐4‐C(CH₃)₃}₂(THF)₂] ( 5 c ?(THF)₂), [Ca{4,4′‐(C₃H₅)₂‐(C₁₀H₈N₂)}(THF)] ( 6 a ?(THF)), [Ca(NC₁₃H₉‐9‐C₃H₅)₂(THF)] ( 7 a ?(THF)), [Ca(4‐C₃H₅‐C₉H₇N)₂(THF)] ( 8 b ?(THF)), and [Ca(1‐C₃H₅‐C₉H₇N)₂(THF)₃] ( 9 a ?(THF)₃) have been characterized by NMR spectroscopy and metal analysis. 9 a ?(THF)₄ and 4 b ?(THF)₃ were additionally characterized in the solid state by X‐ray diffraction experiments. 4 b ?(THF)₃ shows an aza‐allyl coordination mode in the solid state. Based on the results, mechanistic aspects are discussed in the context of previous findings.     

Synthesis and physicochemical characteristics of calcium hydroxyapatite/multiwall carbon nanotubes/collagen nanocomposites

Calcium hydroxyapatite/multiwall carbon nanotubes/collagen nanocomposites were synthesized and subjected to physicochemical analysis. The system CaCl₂-(NH₄)₂HPO₄-multiwall carbon nanotubes-NH₃-H₂O-collagen was investigated at 25°C by the solubility method (Tananaev’s residual concentration method) and by pH measurements. Chemical, X-ray powder diffraction, and thermogravimetric analyses and IR spectroscopy showed that, in the system CaCl₂-(NH₄)₂HPO₄-multiwall carbon nanotubes-NH₃-H₂O-collagen under chosen synthesis conditions, nanocomposites comprising nanocrystalline calcium hydroxyapatite (NCHA), multiwall carbon nanotubes (CNT), and collagen form with the composition Ca₁₀(PO₄)₆(OH)₂ · xCNT · yH₂O · z collagen, where x = 1–5; y = 5.5–7.7, and z = 3, 5, and 10 wt %. The obtained nanocomposites are the products of the coprecipitation of CNT, collagen, and NCHA, which forms in the system by the interaction of CaCl₂ and (NH₄)₂HPO₄.     

Synthesis and Reactivity of Discrete Calcium Imides

Protonolysis of dibenzylcalcium with triphenylsilylamine affords a thf‐coordinated tetrametallic calcium imide with a heterocuboid core structure. The use of calcium bis(tetramethylaluminate) as a precursor for tandem salt metathesis/protonolysis reactions with alkali metal amides of 2,6‐diisopropylaniline and triphenylsilylamine provides access to Lewis acid stabilized monocalcium imides of the type [(thf)₄Ca(μ₂‐NR)(μ₂‐Me)AlMe₂]. Treatment of [(thf)₄Ca(μ₂‐NSiPh₃)(μ₂‐Me)AlMe₂] with phenylsilane results in H?Si addition across the Ca?N imido bond, producing a homoleptic calcium amidoaluminate complex and putative CaH₂ whereas reaction with phenylacetylene leads to protonation of an AlMe moiety to yield the dimeric complex [(thf)Ca{NSiPh₃}{AlMe₂(CCPh)}]₂.