Reaction of N‐Heterocyclic Silylenes with Thioketone: Formation of Silicon–Sulfur Three (Si‐C‐S)‐ and Five (Si‐C‐C‐C‐S)‐Membered Ring Systems

Three‐ and five‐membered rings that bear the (Si‐C‐S ) and (Si‐C‐C‐C‐S ) unit have been synthesized by the reactions of L SiCl ( 1 ; L =PhC(NtBu)₂) and L′ Si ( 2 ; L′ =CH{(C?CH₂)(CMe)(2,6‐iPr₂C₆H₃N)₂}) with the thioketone 4,4′‐bis(dimethylamino)thiobenzophenone. Treatment of 4,4′‐bis(dimethylamino)thiobenzophenone with L SiCl at room temperature furnished the [1+2]‐cycloaddition product silathiacyclopropane 3 . However, reaction of 4,4′‐bis(dimethylamino)thiobenzophenone with L′ Si at low temperature afforded a [1+4]‐cycloaddition to yield the five‐membered ring product 4 . Compounds 3 and 4 were characterized by NMR spectroscopy, EIMS, and elemental analysis. The molecular structures of 3 and 4 were unambiguously established by single‐crystal X‐ray structural analysis. The room‐temperature reaction of 4,4′‐bis(dimethylamino)thiobenzophenone with L′ Si resulted in products 4 and 5 , in which 4 is the dearomatized product and 5 is formed under the 1,3‐migration of a hydrogen atom from the aromatic phenyl ring to the carbon atom of the C? S unit. Furthermore, the optimized structures of probable products were investigated by using DFT calculations.     

Synthesis of spiro[indoline‐3,3′‐pyrrolizines] by 1,3‐dipolar reactions between isatins,l‐proline and electron‐deficient alkenes

Two spiro[indoline‐3,3′‐pyrrolizine] derivatives have been synthesized in good yield with high regio‐ and stereospecificity using one‐pot reactions between readily available starting materials, namely l ‐proline, substituted 1H‐indole‐2,3‐diones and electron‐deficient alkenes. The products have been fully characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry and crystal structure analysis. In (1′RS ,2′RS ,3SR ,7a′SR )‐2′‐benzoyl‐1‐hexyl‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine]‐1′‐carboxylic acid, C₂₈H₃₂N₂O₄, (I), the unsubstituted pyrrole ring and the reduced spiro‐fused pyrrole ring adopt half‐chair and envelope conformations, respectively, while in (1′RS ,2′RS ,3SR ,7a′SR )‐1′,2′‐bis(4‐chlorobenzoyl)‐5,7‐dichloro‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine], which crystallizes as a partial dichloromethane solvate, C₂₈H₂₀Cl₄N₂O₃·0.981CH₂Cl₂, (II), where the solvent component is disordered over three sets of atomic sites, these two rings adopt envelope and half‐chair conformations, respectively. Molecules of (I) are linked by an O—H…·O hydrogen bond to form cyclic R ₆⁶(48) hexamers of (S ₆) symmetry, which are further linked by two C—H…O hydrogen bonds to form a three‐dimensional framework structure. In compound (II), inversion‐related pairs of N—H…O hydrogen bonds link the spiro[indoline‐3,3′‐pyrrolizine] molecules into simple R ₂²(8) dimers.     

Synthesis of [3,3′(4H,4′H)‐Bi‐2H‐1,3‐oxazine]‐4,4′‐diones and Their Hydrolysis

The [3,3′(4H,4′H)‐bi‐2H‐1,3‐oxazine]‐4,4′‐diones 3a – 3i were obtained by [2+4] cycloaddition reactions of furan‐2,3‐diones 1a – 1c with aromatic aldazines 2a – 2d (Scheme 1). So, new derivatives of bi‐2H‐1,3‐oxazines and their hydrolysis products, 3,5‐diaryl‐1H‐pyrazoles 4a – 4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time.     

Highly Stereoselective [3+2] Cycloadditions of Chiral Palladium‐Containing N1‐1,3‐Dipoles: A Divergent Approach to Enantioenriched Spirooxindoles

A catalytic asymmetric [3+2] cycloaddition reaction of chiral palladium‐containing N¹‐1,3‐dipoles with methyleneindolinones has been successfully developed. The reaction allows an efficient construction of 3,3′‐pyrrolinyl spirooxindoles with high yields and excellent stereoselectivities (up to 93 % yield, 19:1 d.r. and >99 % ee). A synthetic application of this methodology is demonstrated and a stereocontrol mechanism is proposed.     

One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

One‐Pot Synthesis of Dispiro[oxindole‐3,3′‐pyrrolidines] by Three‐Component [3+2] Cycloadditions of in situ‐Generated Azomethine Ylides with 3‐Benzylidene‐2,3‐dihydro‐1H‐indol‐2‐ones

An efficient one‐pot, three‐component synthesis of novel dispiro[oxindole‐3,3′‐pyrrolidines] by 1,3‐dipolar cycloaddition of azomethine ylides, in situ generated by reaction of 1,2‐diones with sarcosine and subsequent decarboxylation, with a series of (E)‐3‐benzylidene‐2,3‐dihydro‐1H‐indol‐2‐ones is reported. Molecular complexity is generated in only one synthetic step. All reactions proceed with excellent regioselectivity and in good‐to‐excellent yields. The workup is easy, the reaction times are short, and no catalyst is required.     

Convenient Synthesis of Spiro[benzo[d]pyrrolo[2,1‐b]thiazole‐3,2′‐indenes] Derivatives via Three‐Component Reaction

The three‐component reaction of N‐phenacylbenzothiazolium bromides, aromatic aldehydes and indane‐1,3‐dione in ethanol at room temperature in the presence of triethylamine as base afforded functionalized spiro[benzo[d]pyrrolo[2,1‐b]thiazole‐3,2′‐indenes] in good yields and with high diastereoselectivity. The ¹H NMR data and single crystal structure clearly indicated that the obtained spiro compounds predominately have one diastereoisomer.     

Structural characterization of isomeric 2,3,5‐substituted tetrahydropyrrolo[3,4‐d]isoxazole‐4,6‐diones prepared by cycloaddition of N‐methyl‐C‐arylnitrones to N‐phenyl‐ or N‐methylmaleimide

1,3‐Dipolar cycloaddition reactions of N‐methyl‐C‐arylnitrones with N‐phenyl‐ or N‐methylmaleimide were studied. The reaction of p‐dimethylamino‐, 4‐benzyloxy‐3‐methoxy‐, p‐nitro‐ and p‐chloro‐substituted phenylnitrones with N‐phenylmaleimide gave cis and trans cycloadducts but that of the corresponding phenylnitrones with N‐methylmaleimides only the cis adducts in the case of p‐dimethylamino and 4‐benzyloxy‐3‐methoxy substitution. All cis adducts attain a biased conformation whereas the trans forms are shown (by ¹H NMR at 233 K and ¹³C NMR at 208 K) to be mixtures of two invertomers, namely o‐(N‐lone pair antiperiplanar to 3H; minor) and i‐conformations (3H‐C‐C‐3aH dihedral angle close to 90°; major). PM3 and DFT calculations at the B3LYP/6–31G(d) level of theory prove qualitatively that these two conformers of the trans adduct are of comparable stability and represent energy minima.     

Synthesis of spiro‐pyrazole‐3,3′‐thiopyrano[2,3‐b]pyridines and azolo[a]pyrido[2′,3′:5,6]thiopyrano[3,4‐d]pyrimidines as new ring systems with antifungal and antibacterial activities

Reactions of 2,3‐dihydro‐4‐oxo‐thiopyrano[2,3‐b]pyridine with aldehydes and with DMF‐DMA furnished the 3‐benzylidene and 3‐(N,N‐dimethylamino)‐methylene derivatives. The latter products afforded spiro‐pyrazolo‐3,3′‐thiopyrano[2,3‐b]pyridines and new tetra‐ and penta‐heterocyclic ring systems when treated with nitrilimines and aminoazoles, respectively. A number of the products showed high antifungal and antibacterial activities.     

Conformational dynamics of bis(BF2)‐2,2′‐bidipyrrins revealed by through‐space 13C?19F and 19F?19F couplings

The conformation of [bis‐(N,N′‐difluoroboryl)]‐3,3′‐diethyl‐4,4′,8,8′,9,9′,10,10′‐octamethyl‐2,2′‐bidipyrrin (1) in solution was studied by analyzing the ¹³C? ¹⁹F and ¹⁹F? ¹⁹F through‐space spin–spin couplings. The ¹H and ¹³C NMR spectra were assigned on the basis of nuclear Overhauser effect spectroscopy (NOESY), heteronuclear single‐quantum correlation (HSQC), and heteronuclear multiple‐bond correlation (HMBC) experiments. The ¹⁹F spectrum of 1 was compared with that of 2‐ethyl‐1,3,5,6,7‐pentamethyl‐4,4‐difluoro‐4‐bor‐3a,4a‐diaza‐s‐indacen (2). The ¹⁹F? ¹⁹F through‐space spin? spin coupling in 1 was thus assigned and the coupling constant was obtained by simulating the coupling patterns. The obtained conformation of 1 was compared with those of the known complexes [bis‐(N,N′‐difluoroboryl)]‐3,3′,8,8′,9,9′‐hexaethyl‐4,4′,10,10′‐tetramethyl‐6,6′‐(4‐methylphenyl)‐2,2′‐bidipyrrin (3)and [bis‐(N,N′‐difluoroboryl)]‐9,9′‐diethyl‐4,4′,8,8′,10,10′‐hexamethyl‐3,3′‐bis(methoxycarbonylethyl)‐2,2′‐bidipyrrin (4). The conformational dynamics of 1, 3, and 4 was surveyed by observing the temperature dependence of the through‐space coupling constants between 253 and 333 K. The ¹³C? ¹⁹F and ¹⁹F? ¹⁹F through‐space spin–spin couplings thus confirm similar conformations of different BisBODIPYs in solution in contrast to earlier findings in the solid state. Copyright © 2009 John Wiley & Sons, Ltd.     

Construction and photoluminescence properties of a three‐dimensional ZnII coordination network based on naphthalene‐1,4‐dicarboxylic acid and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene

In recent years, coordination polymers constructed from multidentate carboxylate and pyridyl ligands have attracted much attention because these ligands can adopt a rich variety of coordination modes and thus lead to the formation of crystalline products with intriguing structures and interesting properties. A new coordination polymer, namely poly[[μ₂‐1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene‐κ²N:N′](μ₃‐naphthalene‐1,4‐dicarboxylato‐κ⁴O¹,O^1′:O⁴:O^4′)zinc(II)], [Zn(C₁₂H₆O₄)(C₁₆H₁₄N₂)]_n, has been prepared by the self‐assembly of Zn(NO₃)₂·6H₂O, naphthalene‐1,4‐dicarboxylic acid (1,4‐H₂ndc) and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene (3,3′‐bphte) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. Each Zn^II ion is six‐coordinated by four O atoms from three 1,4‐ndc²⁻ ligands and by two N atoms from two 3,3′‐bphte ligands, forming a distorted octahedral ZnO₄N₂ coordination geometry. Pairs of Zn^II ions are linked by 1,4‐ndc²⁻ ligands, leading to the formation of a two‐dimensional square lattice ( sql ) layer extending in the ab plane. In the crystal, adjacent layers are further connected by 3,3′‐bphte bridges, generating a three‐dimensional architecture. From a topological viewpoint, if each dinuclear zinc unit is considered as a 6‐connected node and the 1,4‐ndc²⁻ and 3,3′‐bphte ligands are regarded as linkers, the structure can be simplified as a unique three‐dimensional 6‐connected framework with the point symbol 4⁴6¹⁰8. The thermal stability and solid‐state photoluminescence properties have also been investigated.     

Reaction of Ketene Dithioacetals with Pyrazolylcarbohydrazide： Synthesis and Biological Activities of Ethyl 5-Amino-1-（5＇-methyl-1 ＇-t-butyl-4＇-pyrazolyl）carbonyl-3-methylthio-1 H-pyrazole-4-carboxylate

The title compound, C16H23N5O3S, ethyl 5-amino-1-(5‘-methyl-1‘-t-butyl-4‘-pyrazolyl)carbonyl-3-methylthio-1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylthioacrylate with 1-t-butyl-5-methyl-4-hydrazinocarbonylpyrazole (4) in refluxed ethanol. The possible mechanism of the above reaction was also discussed. The results of biological test show that the title compound has fungicidal and plant growth regulation activities.     

Solvent‐ and Temperature‐Controlled In Situ Ligand Reactions Mediated by CuII and 3′‐[(E)‐{[(1S,2S)‐2‐Aminocyclohexyl]imino}methyl]‐4′‐hydroxy‐4‐biphenylcarboxlic Acid

Three new compounds, CuL, CuL′, and Cu₂O₂L′′₂ (H₂L=3′‐[(E)‐{[(1S,2S)‐2‐aminocyclohexyl]imino}methyl]‐4′‐hydroxy‐4‐biphenylcarboxlic acid, H₂L′=3′‐[(E)‐{[(1S,2S)‐2‐aminocyclohexyl]imino}methyl]‐4′‐hydroxy‐5′‐nitro‐4‐biphenylcarboxlic acid, H₂L′′=3′‐(N,N‐dimethylamino methyl)‐4′‐hydroxy‐4‐biphenylcarboxlic acid), were selectively synthesized through a controlled in situ ligand reaction system mediated by copper(II) nitrate and H₂L. Selective nitration was achieved by using different solvent mixtures under relatively mild conditions, and an interesting and economical reductive amination system in DMF/EtOH/H₂O was also found. All crystal structures were determined by single‐crystal X‐ray diffraction analysis. Both CuL and CuL′ display chiral 1D chain structures, whereas Cu₂O₂L′′₂ possesses a structure with 13×16 Å channels and a free volume of 41.4 %. The possible mechanisms involved in this in situ ligand‐controlled reaction system are discussed in detail.     

High Reactivity of Strained Seven‐Membered‐Ring trans‐Alkenes

trans‐Oxasilacycloheptenes are highly reactive strained alkenes. Competition reactions showed that these seven‐membered ring trans‐alkenes underwent [4+2] cycloaddition reactions faster than a trans‐cyclooctene. They also reacted with quinones and dimethyl acetylenedicarboxylate to form adducts with high diastereoselectivity. Kinetic studies showed that ring strain increases nucleophilicity by approximately 10⁹.     

A Functionalized Spiro[chlorin‐porphyrin]‐Type ‘Dimer’ Dizinc Complex from Rapid [4+2] Self‐cycloaddition of a Conjugated [β,β′‐Bis(methylene)porphyrinato]zinc

Thermal extrusion of SO₂ from β,β′‐sulfolenoporphyrins is an effective method for in situ generation of β,β′‐bis(methylene)porphyrin which remained unobserved in typical synthetic applications but underwent quickly efficient [4+2]‐cycloaddition reactions with dienophiles.We now report the thermal extrusion of SO₂ from the symmetrical (tetra‐β,β′‐sulfolenoporphyrinato)zinc 1?Zn in the absence of a dienophile (Scheme). In the event, the thermally in situ generated conjugated diene underwent a [4+2] self‐cycloaddition, to give the {spirobi[tri‐β,β′‐sulfolenoporphyrinato]}dizinc 4?2Zn . This chiral (racemic) spirobiporphyrinoid dizinc complex represents the combination of the closely positioned and interacting chromophores of a (porphyrinato)zinc and of a (β‐methylene‐β,β′‐dihydroporphyrinato)zinc. It carries six sulfoleno moieties that are still available for further SO₂ extrusion and cycloaddition reactions.     

Synthesis and Antimicrobial Evaluation of New Monocyclic β‐Lactams

A simple, practical, and efficient approach to synthesize new series of 2‐(3‐(2,4‐dichlorophenoxy)‐2‐(4‐(dimethylamino)phenyl)‐4‐oxoazetidin‐1‐ylamino)‐N‐arylacetamide by Staudinger [2 + 2] cycloaddition reaction. The titled compounds were evaluated for their antibacterial and antifungal activity against eight microorganisms. All the newly synthesized compounds are characterized by IR, ¹H‐NMR, and mass spectroscopic data.     

Methylene‐Bridged Metallocenes with 2,2′‐Methylenebis[1H‐inden‐1‐yl] Ligands: Synthesis,Characterization, and Polymerization Catalysis of a Synthetically Simple Class of C2‐ and C2v‐Symmetric ansa‐Metallocenes

The acid‐catalyzed reaction between formaldehyde and 1H‐indene, 3‐alkyl‐ and 3‐aryl‐1H‐indenes, and six‐membered‐ring substituted 1H‐indenes, with the 1H‐indene/CH₂O ratio of 2 : 1, at temperatures above 60° in hydrocarbon solvents, yields 2,2′‐methylenebis[1H‐indenes] 1 – 8 in 50–100% yield. These 2,2′‐methylenebis[1H‐indenes] are easily deprotonated by 2 equiv. of BuLi or MeLi to yield the corresponding dilithium salts, which are efficiently converted into ansa‐metallocenes of Zr and Hf. The unsubstituted dichloro{(1,1′,2,2′,3,3′,3a,3′a,7a,7′a‐η)‐2,2′‐methylenebis[1H‐inden‐1‐yl]}zirconium ([ZrCl₂( 1′ )]) is the least soluble in organic solvents. Substitution of the 1H‐indenyl moieties by hydrocarbyl substituents increases the hydrocarbon solubility of the complexes, and the presence of a substituent larger than a Me group at the 1,1′ positions of the ligand imparts a high diastereoselectivity to the metallation step, since only the racemic isomers are obtained. Methylene‐bridged ‘ansa‐zirconocenes’ show a noticeable open arrangement of the bis[1H‐inden‐1‐yl] moiety, as measured by the angle between the planes defined by the two π‐ligands (the ‘bite angle’). In particular, of the ‘zirconocenes’ structurally characterized so far, the dichloro{(1,1′,2,2′,3,3′,3a,3′a,7a,7′a‐η)‐2,2′‐methylenebis[4,7‐dimethyl‐1H‐inden‐1‐yl]}zirconium ([ZrCl₂( 5′ )] is the most open. The mixture [ZrCl₂( 1′ )]/methylalumoxane (MAO) is inactive in the polymerization of both ethylene and propylene, while the metallocenes with substituted indenyl ligands polymerize propylene to atactic polypropylene of a molecular mass that depends on the size of the alkyl or aryl groups at the 1,1′ positions of the ligand. Ethene is polymerized by rac‐dichloro{(1,1′,2,2′,3,3′,3a,3′a,7a,7′a‐η)‐2,2′‐methylenebis[1‐methyl‐1H‐inden‐1‐yl]}zirconium ([ZrCl₂( 2′ )])/MAO to polyethylene waxes (average degree of polymerization ca. 100), which are terminated almost exclusively by ethenyl end groups. Polyethylene with a high molecular mass could be obtained by increasing the size of the 1‐alkyl substituent.     

Studying the synthesis of 4‐tert‐butyl‐1,3‐dihydroimidazol‐2‐ones and their corresponding thiones

4‐tert‐Butyl‐1,3‐dihydroimidazol‐2‐ones and 1,3‐dihydroimidazol‐2‐thiones were synthesized from 1‐amino‐3,3‐dimethylbutanone and subjected to alkylation reactions. The latter compounds were S‐alkyl‐ated with iodoacetamide under alkaline conditions. The N¹ N³‐unsubstituted derivative was iodinated and subsequently alkylated with alkylation reagents which previously have been used for the synthesis of anti‐HTV active imidazoles. Unfortunately, the present products were devoid of activity against HTV.     

An Efficient Synthesis of 3′‐Amino‐3′‐deoxyguanosine from Guanosine

3′‐Amino‐3′‐deoxyguanosine was synthesized from guanosine in eight steps and 58% overall yield. The 2′,3′‐diol of 5′‐O‐[(tert‐butyl)diphenylsilyl]‐2‐N‐[(dimethylamino)methylidene]guanosine was reacted with α‐acetoxyisobutyryl bromide and treated with 0.5n NH₃ in MeOH to yield 9‐{2′‐O‐acetyl‐3′‐bromo‐5′‐O‐[(tert‐butyl)diphenylsilyl]‐3′‐deoxy‐β‐D ‐xylofuranosyl]‐2‐N‐[(dimethylamino)methylidene]guanine, which was reacted with benzyl isocyanate, NaH, and then 3.0n NaOH, and finally with Pd/C (10%) and HCO₂NH₄ in EtOH/AcOH to afford 3′‐amino‐3′‐deoxyguanosine.     

New organic–inorganic frameworks incorporating iso‐ and heteropolymolybdate units and a 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium multiple hydrogen‐bond donor

Poly[bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) γ‐octamolybdate(VI) dihydrate], {(C₁₀H₁₆N₄)₂[Mo₈O₂₆]·2H₂O}_n, (I), and bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) α‐dodecamolybdo(VI)silicate tetrahydrate, (C₁₀H₁₆N₄)₂[SiMo₁₂O₄₀]·4H₂O, (II), display intense hydrogen bonding between the cationic pyrazolium species and the metal oxide anions. In (I), the asymmetric unit contains half a centrosymmetric γ‐type [Mo₈O₂₆]⁴⁻ anion, which produces a one‐dimensional polymeric chain by corner‐sharing, one cation and one water molecule. Three‐centre bonding with 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium, denoted [H₂Me₄bpz]²⁺ [N...O = 2.770 (4)–3.146 (4) Å], generates two‐dimensional layers that are further linked by hydrogen bonds involving water molecules [O...O = 2.902 (4) and 3.010 (4) Å]. In (II), each of the four independent [H₂Me₄bpz]²⁺ cations lies across a twofold axis. They link layers of [SiMo₁₂O₄₀]⁴⁻ anions into a three‐dimensional framework, and the preferred sites for pyrazolium/anion hydrogen bonding are the terminal oxide atoms [N...O = 2.866 (6)–2.999 (6) Å], while anion/aqua interactions occur preferentially viaμ₂‐O sites [O...O = 2.910 (6)–3.151 (6) Å].