Amino Acid Functionalization of {Ni6PW9}-Based Clusters Under Hydrothermal Conditions

Two novel hexa-nickel(II)-substituted Keggin-type {Ni₆PW₉}-based tungstophosphates [Ni₆(μ ₃-Tris)(en)₃(Pr)(damp)(H₂O)₂(B-α-PW₉O₃₄)]·10H₂O (1) and [Ni₆(μ ₃-Tris)(en)₃(damp)₂(H₂O)₂(B-α-PW₉O₃₄)]·7H₂O (2) (en = ethylenediamine, Pr = CH₃CH₂COO^?, damp = 2-aminoisobutyrate, Tris = pentaerythritol) were hydrothermally synthesized and characterized by IR spectra, elemental analyses, powder X-ray diffraction, thermogravimetric analyses, and single-crystal X-ray diffraction. Crystal data for 1: orthorhombic, Pca2₁, a = 21.6962(7) Å, b = 20.6398(5) Å, c = 14.7825(4) Å, β = 90º, V = 6619.7(3) Å³, Z = 4; for 2: orthorhombic, Pca2₁, a = 21.6978(9) Å, b = 20.6658(7) Å, c = 14.7767(4) Å, β = 90º, V = 6625.9(4) Å³, Z = 4. 1 consists of a {Ni₆(μ ₃-Tris)(en)₃(Pr)(damp)(H₂O)₂}⁹⁺ core and a [B-α-PW₉O₃₄]^9? (PW₉) unit and is covalently functionalized by one Pr and one damp, as well as en and Tris ligands. The structure of 2 is the same to 1 except that the Pr anion in 1 is substituted by the other damp ligand. Most interestingly, 1 contains four kinds of organic ligands, while 2 includes three kinds of organic ligands, which are first observed in polyoxometalate chemistry.     

Synthesis and crystal structure of diferrocenylmethoxyethylamine

The reaction of diethanolamine with diferrocenylmethyl carbonium (2) that was generated by diferrocenylmethanol (1) treated with BF₃ in CH₂Cl₂ provided the synthesis of title compound diferrocenylmethoxyethylamine (3). The structure of 3 was determined by the X-ray diffraction (XRD) with crystal data: monoclinic P2₁/n space group and a=5.8419(14) Å, b=13.572(3) Å, c=23.839(6) Å, α=90°, β=91.827(5)°, γ=90°, V=1889.2(8) Å³, Z=4, D _c =1.558 mg·m^?3, μ=1.548 mm^?1, F(000)=920. The intra- and inter-molecular H bonding modes in 3 were demonstrated both in molecular crystal structure and IR spectral characterization.     

Synthesis,Structural Characterization and Properties of Two Strontium Borates Constructed from Oxo Boron Clusters

Two strontium borates Sr₂[B₆O₉(OH)₄] (1) and Sr₂B₅O₉(OH)·H₂O (2), with acentric structures have been synthesized under hydro/solvothermal conditions. Compound 1 is reported for the first time in the strontium borates system, and it crystallizes in the monoclinic space group P2₁ with unit cell parameters a = 6.8445(5) Å, b = 8.7033(6) Å, c = 8.4632(6) Å, β = 100.581(6)°, V = 495.58(6) ų and Z = 2. Its structure consists of unusual borate layers of 3, 11-membered rings, which are interconnected via Sr–O ionic bonds and hydrogen bonds to generate a 3D supramolecular network. Compound 2 is a known strontium borate, crystallizing in the monoclinic space group C ₂ with a = 10.161 (13) Å, b = 7.965(4) Å, c = 6.393(11) Å, β = 128.0(2)°, V = 407.7(14) ų and Z = 2. Second-harmonic generation measurements on the powder samples reveal that 1 and 2 exhibits good SHG efficiency about 1.5 and 2 times that of KDP (KH₂PO₄) powder respectively.     

Syntheses and Crystal Structures of Two New Pentaborates Templated by Transition-Metal Complexes

Two new pentaborates [M(dap)₃][B₅O₆(OH)₄]₂·H₂O (M = Co (1) and Ni (2); dap = 1,2-diaminopropane) have been hydrothermally synthesized. Both structures were determined by single crystal X-ray diffraction and further characterized by elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence spectroscopy. Two compounds are isostructural and consist of isolated pentaborate [B₅O₆(OH)₄]^? anions and [M(dap)₃]²⁺ complex cations. The anionic [B₅O₆(OH)₄]^? groups are linked by extensive hydrogen bonds to form a 3-D supramolecular framework with large channels, in which the transition-metal complex templates are located. The luminescent properties of 1 and 2 were studied, and blue luminescence occurs with an emission maximum at 405 and 408 nm upon excitation at 332 and 328 nm respectively. Crystal data: 1, monoclinic, space group P2₁/c (No. 14), a = 9.7159(5) Å, b = 29.3372(19) Å, c = 11.5121(6) Å, β = 103.286(5)°, V = 3193.6(3) ų, Z = 4; 2, monoclinic, space group P2₁/c, a = 9.7264(4) Å, b = 29.3810(16) Å, c = 11.5185(6) Å, β = 103.249(4)°, V = 3204.0(3) ų, Z = 4.     

New synthetic routes for the preparation of the triangular trinuclear clusters of tungsten-containing bromine atoms as terminal ligands: Structural characterization of [W3S4Br3(depe)3]PF6·0.5C7 H8 and [W3S4Br3(depe)3]Br·2CH3OH

Synthetic methods are reported for the preparation of compounds containing the trinuclear triangular cluster [W₃S₄Br₃(depe)₃[⁺. These involve reactions between WBr₅ and NaB(C₂ H₅)₃H or NaBH₄ as reducing agent in THF, and subsequent addition of methanolic solutions of NaHS and depe ligand. Both compounds, [W₃S₃Br₃(depe)₃]PF₆·0.5C₇H₈,1, and [W₃S₄Br₃(depe)₃]Br·2CH₃OH,2, are characterized by x-ray single crystal studies. Compounds1 and2 crystallize in space group \(P\bar 1\) . For1,a=10.427 (3) Å,b=15.415(4) Å,c=18.140(5) Å, α=79.36(2)°, β=73.59(2)°, γ=81.54(2)°, andV=2734.8(2) ų;R=0.050 and for 2a=10.491(3) Å,b=15.074(3) Å,c=18.246 Å, α=95.76(2)°, β=105.82(2)°, γ=98.18(2)°, andV=2718.4(3) ų;R=0.081. The two cations in1 and2 possess C₃ symmetry. The W-W distances are in the range 2.783?2.891 Å (for1) and 2.778?2.785 Å (for2) and the average W-Br distances in1 and2 are 2.616[2] Å and 2.594[4] Å, respectively. Each metal atom in the [W₃S₄Br₃(depe)₃]⁺ ions is attached to one capping sulfur atom, two bridging sulfur atoms, one bromine atom, and one chelating depe ligand. One P atom in depe ligand istrans to μ₃-S and the otherP atom istrans to a μ₂-S atom. UV-Vis and NMR spectra for these compounds are also reported.     

1D Chain-Like Architecture in Anderson Heteropolymolybdate {[Eu(H2O)6]2(TeMo6O24)}·6H2O: Synthesis and Characterization

A new Anderson-based heteropolymolybdate {[Eu(H₂O)₆]₂(TeMo₆O₂₄)}·6H₂O (1) has been hydrothermally synthesized and characterized by elemental analyses, IR, thermal stability analysis, XRD and single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P-1, a = 9.4023(6) Å, b = 10.2530(7) Å, c = 10.6525(10) Å, α = 101.583(7)º, β = 108.024(7)º, γ = 107.150(6)º, V = 883.60(12) ų, Z = 1, R₁ = 0.0338, wR₂ = 0.0849. Compound 1 exhibits 1D chain-like structure formed by the alternative connection between Anderson type polyoxoanions [TeMo₆O₂₄]^6? and Eu³⁺ along a-axis. Compound 1 displays good fluorescent emission of the Eu³⁺ ion at room temperature.     

Synthesis and X-ray crystal structure analysis of Fe2(CO)6(μ3-S)2Pd(bipy)

The reaction of Fe₂(CO)₆(μ-S₂),1 withbis(dibenzylideneacetone)-palladium, Pd(dba)₂, in the presence of 2,2′-bipyridine yielded the new compound Fe₂(CO)₆(μ ₃-S)₂Pd(bipy),2 in good yield (66%). Compound2 was characterized by IR,¹H NMR and single-crystal X-ray diffraction analyses. Compound2 contains a Pd(bipy) group that has been inserted into the S-S bond of1. Crystal data for2: space group P2₁/n,a=10.019(2) Å,b=25.414(5) Å,c=7.714(2) Å,β=90.26(2)°,Z=4, 1436 reflections,R=0.023.     

Cluster Complexes of Polythioether Macrocycles: The Synthesis and Molecular Structures of Ru6(CO)13(cis-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C) and Ru6(CO)13(trans-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C)

The reaction of a mixture of cis-3,7,11-trimethyl-1,5,9-trithiacyclododecane, cis-Me₃12S3, 1 and trans-3,7,11-trimethyl-l,5,9-trithiacyclododecane, trans-Me₃12S3, 2, with Ru₆(CO)₁₇(μ ₆-C), 3, yielded three new cluster compounds Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 4, and two isomers of Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 5a and 5b. The molecular structures of 4 and 5b were established by single crystal X-ray diffraction analyses. In both complexes, the macrocycles have adopted tridentate coordination with one of the sulfur atoms in a bridging position. Two carbonyl ligands occupy bridging positions in each compound. Crystal Data for 4·Me₂CO: space group=P2₁/n, a=11.295(1) Å, b=17.547(3) Å, c=20.318(3) Å, β=93.71(1)°, Z=4, 2900 reflections, R=0.025. Crystal Data for 5b·1.5 C₆H₆: space group=Pbca, a=31.8900(8) Å, b=23.4330(6) Å, c=21.6240(4) Å, Z=16, 12163 reflections, R=0.040.     

Temperature-Dependent Organic Functionalization of {Ni6PW9} Species: from Isolated Clusters to 1D Chain

Four new hexa-nickel(II)-substituted Keggin-type tungstophosphates [Ni₆(μ₃-OH)₃(oeen)₃(H₂O)₃(B-α-PW₉O₃₄)]·6H₂O (1, oeen = N-(2-hydroxyethyl)enediamine), [Ni₆(μ₃-OH)₃(oeen)₃(H₂O)₄(B-α-PW₉O₃₄)]₂·13H₂O (2), [Ni₆(μ₃-OH)₃(oeen)₂(tran)(H₂O)₃(B-α-PW₉O₃₄)]·3H₂O (3, tran = 1,4,7-triazonane) and [Ni₆(μ₃-OH)₃(oeen)₂(tran)(H₂O)₂(B-α-PW₉O₃₄)]·6H₂O (4) have hydrothermally made by controlling their reaction temperatures. 1–4 have been characterized by elemental analyses, IR spectra, powder X-ray diffraction, thermogravimetric analyses and single-crystal X-ray diffraction, respectively. Structural analyses reveal that they consist of {Ni₆(μ₃-OH)₃(H₂O) _n }⁹⁺ cores and B-α-PW₉O₃₄ (PW₉) units, and further are stabilized by organic neutral oeen/tran molecules. 1–3 are isolated clusters while 4 is the 1D chain structure. It should be noted that the tran molecules in 3 and 4 are derived from the oeen molecules in the starting materials.     

Three types of heterometallic structural motifs based on [Mo(CN)8]3−/4− anion and MnII cation as building blocks

The reaction between K₃[Mo(CN)₈] · H₂O and MnCl₂ · 4H₂O in different reaction conditions have obtained three new bimetallic cyanide-bridged compounds, namely, {(tetrenH₂)_0.5[Mn(H₂O)₂][Mo^V(CN)₈] · 2H₂O} _n (1) (where, tetren is tetraethylenepentamine), {[Mn₂(H₂O)₄][Mo^IV(CN)₈] · 3H₂O} _n (2), and {[Mn₂(H₂O)₄][Mo^IV(CN)₈] · 4H₂O} _n (3). Compound 1 crystallizes in the orthorhombic system with space group Cmc21 and unit cell constants a = 7.8234(15), b = 26.013(5), c = 10.021(2) Å, β = 90°, and Z = 4. Compound 2 crystallizes in the monoclinic system with space group P21/n and unit cell constants a = 7.3329(11), b = 14.372(2), c = 18.070(3) Å, β = 90.869(2)°, and Z = 4. Compound 3 crystallizes in the tetragonal system with space group I4/m and unit cell constants a = b = 11.9371(8), c = 13.2930(18) Å, β = 90°, and Z = 4. X-ray single-crystal structures reveal that the Mo centers adopt a distorted square antiprism coordination environment for 1 and 3, while 2 closed to a bicapped trigonal prism. For these complexes, all the Mn^II centers in the extended structure adopt distorted octahedron geometry. For 1, each Mo^V coordinated via four cyanide groups to four Mn^II ions, and the other four cyanide groups are terminal, forming a two-dimensional framework. For 2, the Mo^IV center of structural unit coordinated via four cyanide groups to four Mn(1), and the other four cyanide groups coordinated to four Mn(2), forming a three-dimensional framework. For 3, each [Mo^IV(CN)₈]^4? building block is linked to Mn^II ions through its eight CN ligands, and each Mn^II center is connected to four Mo units forming a three-dimensional framework. In addition, magnetic studies of these complexes have also been presented.     

Metal thiolate compounds: Processable ceramic precursors

Full crystallographic characterization has been obtained for [Hg(SBz)₂]_∞ (9), ClHgSBz · TMEDA (10), [ClHgS-i-Pr]_∞ (11), [ClHg(S-neo-Pent)·0.5Py]_∞ (12), In[S-2,4,6-(i-Pr)₃C₆H₂]₃·2MeCN (13), [In(S-2-MeO,5-Me, C₆H₃)₃]₂ (14) and In(S-o-C₆H₄CH₂N(CH₃)₂)₃ (15). Relevent metal thiolate interactions, terminal and bridging, are highlighted within the realm of thermolytic conversion of these species into binary metal thiolates. Pertinent crystallographic data for these compounds include:9: C2/c,a=22.599(4)Å,b=4.334(1)Å,c=29.596(5)Å,β=106.76(1)°,V=2775.6ų,Z=8,R=3.6%;10: P $\bar 1$ ,a=8.136(2)Å,b=9.958(7)Å,c=11.834(3)Å,α=108.71(2)°,β=92.93(2)°,γ=109.05(2)°,V=845.3ų,Z=2,R=5.0%;11: C2,a=21.430(7)Å,b=4.678(2)Å,c=6.724(2)Å,β=90.43°,V=674.0ų,Z=2,R=3.9%;12: C2,a=16.732(2)Å,b=11.200(1)Å,c=11.929(2)Å,β=104.21(1)°,V=2167.1ų,Z=4,R=3.5%;13: P $\bar 1$ ,a=13.680(8)Å,b=13.815(6)Å,c=15.155(9)Å,α=77.77(4)°,β=72.57(4)°,γ=88.18(4)°,V=2669.1ų,Z=8,R=12.0%;14: C2,a=8.323(2)Å,b=24.970(4)Å,c=12.466(2)Å,β=104.32(2)°,V=2510.1ų,Z=4,R=8.2%;15: P2₁/c,a=17.587(5)Å,b=11.786(2)Å,c=13.865(2)Å,β=101.66(2)°,V=2814.6ų,Z=4,R=3.2%. The molecules-to-materials transition, from a relatively simple divalent system, to the more mechanistically complex trivalent metal system is outlined.     

A three-dimensional porous and magnetic framework constructed from copper salt and 5-Methyltetrazole: [Cu8(Metz)9](OH)·xH2O

A new compound of [Cu₈(Metz)₉](OH)·xH₂O (x≈3) (1) (Metz = 5-Methyltetrazole) has been prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The crystal is of hexagonal, space group P6₃/m with a = b = 13.988(1) Å, c = 16.309(2) Å, α = β = 90°, γ = 120°, V = 2 763.5 (4) Å³, Mr = 1327.13, D _c = 1.595 g cm^?3, Z = 2, F(000) = 1 316, μ = 3.076 mm^?1, the final R = 0.0494 and wR = 0.1532 for 1,731 observed reflections (I > 2σ(I)). In this compound, the [(Cu^II)₂(Cu^I)₆(Metz)₉]⁺ cationic clusters are connected together through Cu^I cations and Metz ligands and result in a three-dimensional framework. Remarkable, three-dimensional intersecting channels exist in it. The variable temperature magnetic investigations indicate that 1 exhibits typical antiferromagnetic behaviors. N₂ gas adsorption measurements at 77 K showed that compound 1 possesses permanent porosities.     

Acid Co(II) and Ni(II) trifluoroacetate complexes: Synthesis and crystal structure

Anhydrous and partially hydrated acid trinuclear trifluoroacetates of divalent transition metals of the composition [M₃(CF₃COO)₆(CF₃COOH)₆)](CF₃COOH) and [M₃(CF₃COO)₆(CF₃COOH)₂(H₂O)₄)](CF₃COOH)₂, respectively, where M = Co (I, III) Ni (II, IV), were synthesized and studied by X-ray diffraction. Complexes I and II were obtained by crystallization from solutions of M(CF₃COO)₂ · 4H₂O in trifluoroacetic anhydride; complexes III and IV were synthesized under the same conditions with the use of 99% trifluoroacetic acid as a solvent. Crystals I are triclinic: space group $P\bar 1$ , a = 13.199(6) Å, b = 14.649(6) Å, c = 15.818(6) Å, α = 90.04(4)°, β = 114.32(4)°, γ = 108.55(4)°, V = 2611.3(19) ų, Z = 2, R = 0.0480. Crystals II are trigonal: space group $R\bar 3$ , a = 13.307(2) Å, c = 53.13(1) Å, V = 8148(2) ų, Z = 6, R = 0.1112. Crystals III are triclinic: space group $P\bar 1$ , a = 9.001(8) Å, b = 10.379(9) Å, c = 12.119(9) Å, α = 83.67(5)°, β = 72.33(5)°, γ = 83.44(5)°, V = 1068.3(15) ų, Z = 1 Å, R = 0.1031. Crystals IV are triclinic: space group $P\bar 1$ , a = 9.121(18) Å, b = 10.379(2) Å, c = 12.109(2) Å, α = 84.59(3)°, β = 72.20(3)°, γ = 82.80(3)°, V = 1080.94(40) ų, Z = 1, R = 0.0334.     

Solvothermal Syntheses and Crystal Structures of Two Novel Borates: [(CH3)3NH][B5O6(OH)4] and Na2[H2TMED][B7O9(OH)5]2

Two novel borates [(CH₃)₃NH][B₅O₆(OH)₄] (I) and Na₂[H₂TMED][B₇O₉(OH)₅]₂ (II) have been synthesized under solvothermal conditions, and characterized by elemental analyses, FT-IR spectroscopy, and single crystal X-ray diffraction. Crystal data for I: monoclinic, P2₁/c, a = 9.3693(11) Å, b = 14.0375(17) Å, c = 10.0495(9) Å, β = 91.815(9)°, Z = 4. Crystal data for II: monoclinic, P2₁/c, a = 11.6329(2) Å, b = 11.9246(3) Å, c = 10.2528(2) Å, β = 100.178(2)°, Z = 4. Their crystal structures both have 3D supramolecular framework with large channels constructed by O–H···O hydrogen-bonding among the polyanions of [B₅O₆(OH)₄]^? or [B₇O₉(OH)₅]^2? clusters. The templating organic amines cations in I and II are both located in the channels of 3D supramolecular frameworks, respectively, and interact with the polyborate frameworks both electrostatically and via hydrogen bonds of N–H···O. Na₂[H₂TMED][B₇O₉(OH)₅]₂ is the first example of heptaborate co-templated by alkali metal and organic base, which is also rare in borates. The photoluminescence property of the synthetic sample of Na₂[H₂TMED][B₇O₉(OH)₅]₂ in the solid state at room temperature was also investigated by fluorescence spectrophotometer.     

Synthesis and Crystal Structure of Copper(I) Chloride π-Complexes with N-Allyl- and N,N'-Diallylpiperazinium Dichlorides: [C3H5NH(CH2)4NH2]Cu2Cl4and [C3H5NH(CH2)4NHC3H5]0.5CuCl2

The crystals of copper(I) π-complexes with N-allyl piperazine derivatives, [C₃H₅NH(CH₂)₄NH₂]Cu₂Cl₄(I) and [C₃H₅NH(CH₂)₄NHC₃H₅]_0.5CuCl₂(II), were prepared by alternating-current electrochemical synthesis. X-ray diffraction study showed that compounds Iand IIcrystallize in the monoclinic system: for I, space group P2₁/a, a= 10.254(4) Å, b= 12.306(4) Å, c= 10.656(4) Å, γ = 98.83(3)°, V= 1329(2) ų, Z= 4, R= 0.0457 for 1334 independent reflections; for II, space group P2₁/n, a= 10.187(2) Å, b= 7.283(2) Å, c= 10.480(3) Å, γ = 100.72(2)°, V= 764.0(6) ų, Z= 4, R= 0.0371 for 1025 independent reflections. The structure of Iis composed of {Cu₂Cl₄(C₇H₁₆N₂)}₂dimers linked by fairly strong (N)H···Cl hydrogen bonds (2.35(4) Å). The structure of IIconsists of centrosymmetrical dimeric Cu₂Cl₄ ^2–anions, whose copper atoms coordinate the allyl groups of different centrosymmetrical organic cations. The dimer–ligand chains are stretched along the [ $ {11} $ 0] direction and are joined by hydrogen contacts (N)H···Cl (2.62(4) Å).     

Synthesis and study of tetraamminecobalt hydrogen hexamolybdometalates(III)

Tetraamminecobalt hydrogen hexamolybdoferrate [Co(NH₃)₄] · H[FeMo₆O₁₈(OH)₆] · 6H₂O (I) and tetraamminecobalt hydrogen hexamolybdogallate(III) [Co(NH₃)₄] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetry, IR spectroscopy, and X-ray diffraction. Crystals of I and II are monoclinic; a = 16.21 Å, b = 5.43 Å, c = 12.32 Å, β = 119.63°, V = 1092.11 ų, ρ_calcd = 2.21 g/cm³, and Z = 1 for I; a = 16.24 Å, b = 5.59 Å, c = 12.29 Å, β = 119.79°, V = 1064.05 ų, ρ_calcd = 2.15 g/cm³, and Z = 1 for II. Compounds I and II were used as catalysts for soft oxidation of natural gas.     

Two new organic borates with the large [B14O20(OH)6]4− oxoboron clusters

Two new borate clusters, [NH₃(CH₂)₃NH₃]₂[B₁₄O₂₀(OH)₆] (1) and [NH₃(CH₂)₆NH₃]₂[B₁₄O₂₀(OH)₆] (2), have been made under solvothermal conditions and characterized by single-crystal X-ray structural analysis. Also their IR and UV–Vis spectroscopy, thermogravimetric analysis, and elemental analysis have been investigated, respectively. Crystal data for 1: triclinic, P-1, a = 8.8049(4) Å, b = 9.1585(5) Å, c = 10.1912(5) Å, α = 74.925(4)°, β = 80.987(4)°, γ = 67.495(5)°, Z = 1. Crystal data for 2: triclinic, P-1, a = 9.2010(4) Å, b = 9.8663(4) Å, c = 11.4191(4) Å, α = 107.014(4)°, β = 92.514(3)°, γ = 107.265(4)°, Z = 1. The structures consist of isolated 8-membered boron ring made of the [B₇O₁₀(OH)₃]^2?cluster subunits. UV–Vis spectral investigation indicates that they are wide-band-gap semiconductors. Fluorescence spectroscopy indicates that they are potential blue light materials.     

Hydrothermal Synthesis, Crystal Structure and Properties of a New Porous Zinc Arsenite Zn3As2O6 with the Novel Helical Zn–O Chains

A new porous zinc arsenite Zn₃As₂O₆ 1 has been synthesized under hydrothermal conditions, and characterized by X-ray single crystal diffraction, IR and TG analysis. The structural analysis reveals that compound 1 is constructed from a network of AsO₃ trigonal pyramids and ZnO₄ tetrahedra, and represents a 3D framework with one-dimensional 8-membered-ring channels and interesting helical Zn–O chains. Crystal data for 1: Monoclinic, space group P2(1)/c, a = 8.250(4) Å, b = 5.186(3) Å, c = 15.824(9) Å, β = 97.379(9)°, V = 671.4(6) Å³, Z = 4, R1 = 0.0481, and wR2 = 0.0834.     

Diethyltin-Containing Tungstoarsenate(V), [{Sn(C2H5)2}3(H2O)6(A–α–AsVW9O34)]3−

Reaction of (C₂H₅)₂SnCl₂ with the trilacunary 9-tungstoarsenate(V) [A–α–AsW₉O₃₄]^9? in aqueous pH 5 medium resulted in the diethyltin-containing polyanion [{Sn(C₂H₅)₂}₃(H₂O)₆(A–α–As^VW₉O₃₄)]^3? (1), which crystallized as a hydrated guanidinium salt, [C(NH₂)₃]₃[{Sn(C₂H₅)₂}₃(H₂O)₄(A–α–As^VW₉O₃₄)]·9H₂O (1a). Polyanion 1 represents the first example of a diethyltin-containing polyanion. The diethyltin groups are bound to the trilacunary Keggin units via two Sn–O(W) bonds involving edge-shared WO₆ octahedra. Each Sn atom also has two terminal, cis-related water ligands, and two terminal, trans-related ethyl groups. Multinuclear (¹H, ¹³C, ¹¹⁹Sn, ¹⁸³W) NMR spectrometry indicated that polyanion 1 is stable in solution. Compound 1a was structurally characterized in the solid state by single-crystal XRD, FT-IR, as well as thermogravimetric and elemental analyses. Single-crystal X-ray analysis showed that 1a crystallizes in the orthorhombic system, space group P _nma , with a = 23.5280(10) Å, b = 15.5435(6) Å, c = 18.6191(9) Å, V = 6809.1(5) ų and Z = 4. The structure of 1a is an extended 2D assembly of individual polyanion units 1 linked via Sn–O(W) bridges.     

Synthesis, characterization and crystal structures of the tetrachlorocuprate and tetrabromocadmate salts of the antimalarial mefloquine

Two new compounds, bis (DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrachlorocuprate(II) tetrahydrate [LH⁺]₂[CuCl₄]^2??4H₂O 1 [L = mefloquine] and bis(DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrabromocadmate (II) bis(methanol) [LH⁺]₂[CdBr₄]^2?·2CH₃OH 2, have been synthesized and characterized by elemental analysis, ¹H-NMR and IR spectroscopy. Single-crystal X-ray diffraction analysis of 1 showed the structure to be ionic with formula unit comprising two protonated monocationic mefloquine molecules of opposite chirality, a tetrachlorocuprate (II) anion and a complement of four water molecules, disordered over several sites. The crystals are orthorhombic, space group Pnma, a = 9.6975(1) Å, b = 29.5385(3) Å, c = 15.9423(1) Å, V = 4566.67(7) ų, Z = 4. The formula unit of compound 2 comprises two protonated monocationic mefloquine molecules, a tetrabromocadmate(II) anion and two molecules of methanol. The crystals are orthorhombic, space group Fdd2, a = 17.2185(5) Å, b = 55.456(2) Å, c = 9.5140(3) Å, V = 9084.6(5) ų, Z = 8. The mefloquine molecule is protonated at the piperidinyl N atom and extensive hydrogen bonding occurs in both crystal structures. The conformation of the mefloquine cation in 1 and 2 is very similar to that recently observed in other salts of the drug, confirming its relevance in the context of antimalarial action.