Complexation with diol host compounds. Part 3. Molecular inclusion of 4-methylcyclohexanone and 2-methylcyclohexanone by the host,trans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene

The structures of the 12 molecular complexes oftrans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene with 4-methylcyclohexanone (1) and with 2-methylcyclohexanone (2) have been determined by X-ray crystallography. The crystal data are as follows: Compound (1):P2₂/c,a=8.838(2) Å,b=8.92(1) Å,c=20.879(8)=Å,=98.67(2)°,V=1627(2) ų,Z=2 andR=0.062 for 2201 unique MoK reflections; Compound (2):P¯1,a=8.917(3) Å,b=9.900(2) Å,c=11.250(4) Å,a=68.72(2)°,=64.39(3)°, =74.86(2)°,V=828.1(5) ų,Z=1 andR=0.098 for 2563 unique reflections. Both inclusion compounds exhibit O-HO=C hydrogen bonding interactions. The thermal properties of these compounds have been characterized by DTA and TGA thermograms.     

Crystal structure of 751-1751-1751-1751-2751-2751-2

The title compound crystallizes in the centrosymmetric triclinic space group (No. 2) witha=10.818(1)Å,b=10.876(1)Å,c=11.072(2)Å, =98.74(1)°, =98.83(1)°, =96.61(1)°,V=125906(3)ų andZ=2. Interatomic distances include Fe–P=2.243(2)Å, Fe–CO=1.771(6)–1.781(5)Å, Fe–C(C₅H₅)=2.074(6)–2.103(5)Å and P–F=1.511(6)–1.571(4)Å.     

Crystal and molecular structure of powerine: Methyl 10,17-dihydroxy-(16β,17β,20α)-yohimban-16-carboxylate

The methanol adduct of powerine [methyl 10,17-dihydroxy-(16,17,20)-yohimban-16-carboxylate], C₂₁H₂₆N₂O₄. CH₃ OH, crystallizes in the orthorhombic space groupP2₁2₁2₁ (no. 19) with cell dimensionsa = 8.558(3),b = 14.162(7),c = 16.993(7) Å. The crystal and molecular structure has been determined by X-ray diffraction analysis and refined using full-matrix least squares methods to a reliability index,R, of 0.090 with 1139 observed (F 2.5 _F ) intensities. With the configuration at C15 arbitrarily assigned those at the chiral centers C3-H, C16-CO₂Me, C17-OH and C20-H are respectively ,,,: theC-D ring junction istrans and that ofD-E iscis. All bond lengths and bond angles are normal.     

Crystal structures of the new diphosphates,K2NiP2O7 and K6Sr2Ni5(P2O7)5

Crystalline K₂NiP₂O₇ (I): monoclinic, P2₁,a=9.230(2),b=17.540(8),c=8.319(9)Å, =91.44(2)°,Z=8,d _calc=3.067 g cm^–3, MoK =0.71069Å,R/R _w=6.5/9.4%, is characterized by the existence of face sharing NiO₆ octahedra with Ni–Ni separation of 2.827 Å (Ni–O; 1.93(2)–2.17(2)Å). K⁺ is seen in sites of seven, six, and fivefold coordination (K–O, averages; 2.83(2), 2.81(2), and 2.77(2)Å, respectively) P₂O₇ ^4– groups are observed in semieclipsed conformation. K₆Sr₂Ni₅(P₂O₇)₅ (II) crystallizes in monoclinic space group P2₁/c;a=11.038(7),b=9.533(13),c=7.438(2)Å, =100.13(4)°,D _calc=3.309 g cm^–3,Z=2,R/R _w=6.4/8.1%. Nickel atoms are distributed on planes parallel to the crystallographic (100) plane at =0 and =0.5. On the planes, =0, Ni²⁺ ions form successive linked trimers of edge sharing NiO₆ octahedra (Ni–Ni, 3.018(1), 3.008(1)Å; Ni–O, av 2.07(2)Å). The intermediate planes (=0.5) contain isolated and six coordinate Ni²⁺ ions (Ni–O av. 2.09(2)Å). Seven-coordinate potassium ions (K–O, av. 2.74(2)Å) are located on intermediate planes at =0.25 and 0.75. P₂O₇ ^4– groups are found in eclipsed conformation. Strontium atoms are located between nickel and potassium planes and are surrounded by seven oxygen atoms (Sr–O, av. 2.586(2)Å).     

Crystal and molecular structure of: 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octan-7-one and 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octane

X-ray crystallographic studies of the two title compounds have shown that the molecules crystallize in the same triclinic space group, , with very similar cell dimensions. For C₂₁H₂₁BrO₄,a=12.056(5),b=13.206(5),c=7.595(3)Å, =90.38(3), =106.07(3) and =124.42(3)° and for C₂₁H₂₃BrO₃,a=12.076(6),b=13.090(5),c=7.490(3)Å, =92.65(5), =104.90(5) and =124.55(5)°. Both compounds possess the oxabicyclo[3.2.1]octane bridged ring system and differ only at the carbon to the ring oxygen where the Csp³ in the ether is replaced by Csp²=O in the lactone. Both cyclohexane rings adopt distorted chair conformations and the lactone and ether rings approximate closely to the envelope conformation. The bromine substituent at C(4) results in distortion of the naphthalene ring. Both molecules pack with the naphthalene rings parallel to each other with interplanar spacings of 3.71 Å in the ether and 3.66Å in the lactone.     

4- and 5-nitroindane

Mononitration of indane produces a mixture of 4- and 5- nitroindanes. Crystallization from mixtures occurs after distillation improves composition of a major component to above 80%. 4-Nitroindane: triclinic, space group (#2),a=7.332(4) Å,b=8.304(4) Å,c=8.358(4) Å, =61.43(4)°, =67.60(4)°, =70.15(4)°,V=405.4(4) ų,Z=2. Non-H-atoms are nearly planar, aliphatic H's are eclipsed. 5-Nitroindane: monoclinic, space groupP2₁/c (#14),a=10.946(8) Å,b=15.643(10) Å,c=9.415(6) Å, =92.34(5)°,V=1611(2) ų,Z=8. Non-H-atoms in the two molecules differ in torsion of the nitro group with respect to indane and fold of the nonbenzylic methylene group. Semiempirical calculations (PM3) suggest that distorsion from planarity may be associated with the two lowest energy vibrational modes. Uv, ir, ms, proton, and¹³C-nmr spectra are correlated with the solid state structures.     

Crystal structure and spectroscopic study of 4-(N-acetyl) cysteinyl-6,7-dimethoxy-2,2-dimethyl-3-hydroxybenzo-1H-pyran,a potential metabolite of glutathione conjugation of precocene II 3,4-epoxide

The X-ray crystal structure of the title compound has been determined. The crystals are monoclinic:P2₁/a, a=9.804(7),b=20.544(4),c=13.288(3) Å,=105.94(4)°,V _c=2561.9 ų,Z=4,D _x=1.39Mg m^–3, (MoK)=0.71069 Å. The structure was solved by direct methods and refined with 2147 reflections to a finalR value of 0.072. The 1h-pyran ring departs from ideal symmetry towards a half-chair conformation. Mass, IR, and¹H NMR spectra are also reported.     

Crystal structures of (I) 2-(9,9-dipropylfluorene-2-yl)-9,9- dipropylfluorene and (II) 2-(1,1-dimethylpropyl)-7- {4-[(1,1-dimethylpropyl)-9,9-diethylfluoren-2-yl]phenyl}-9,9-diethylfluorene and (III) 2-(4-ethylphenyl) -7-[7-(ethylphenyl)-9,9-dipropylfluoren-2-yl]-9,9-dipropylfluorene

The crystal structures of the three fluorene related molecules, (I) 2-(9,9-dipropylfluorene-2-yl)-9,9-dipropylfluorene, [Exalite 384, C₃₈H₄₂], (II) 2-(1,1-dimethylpropyl)-7-{4-[(1,1-dimethylpropyl)-9,9-diethylfluoren-2-yl] phenyl}-9,9-diethylfluorene, [Exalite 404, C₅₀ H₅₈], and (III) 2-(4-ethylphenyl)-7-[7-(ethylphenyl)-9,9-dipropylfluoren-2-yl]-9,9-dipropylfluorene, [Exalite 416, C₅₄H₅₈], have been determined. Structural details reveal a novel new bonding arrangement at the C2 atoms of symmetry-related fluorene moieties in all three molecules producing a linear type array with an inversion center connecting adjacent asymmetric units within each molecule. Exalite 384 is monoclinic, space group P2₁/c with a = 9.002(2) Å, b = 16.275(4) Å, c = 10.525(1) Å, = 103.05(1), and V = 1502.1(5) ų with Z = 4, for d _calc = 1.103 g/cm³. Exalite 404 is triclinic, space group P1 with a = 10.383(1) Å, b = 13.404(2) Å, c = 7.7007(9) Å, = 105.296(9), = 104.23(1), = 73.707(9), and V = 974.9(2) ų with Z = 2, for d _calc = 1.141. Exalite 416 is monoclinic, space group P2₁/c with a = 15.99(10) Å, b = 11.178(8) Å, c = 23.766(4) Å, = 104.21(4), and V = 4117(4) ų with Z = 4, for d _calc = 1.141 g/cm³.     

Crystal and molecular structure of 5-bromo-pentacyclo[4.3.0.02,5.03,8.04,7]nonane-4-carboxylic acid,C10H9BrO2

The structure of the title compound, C₁₀H₉BrO₂, was determined by X-rays.M _r =241.08, triclinic, space groupP¯1,a=5.800(1),b=6.441(1),c=12.030(1) Å,=92.90(1)°,=95.65(2)°, =95.69(2)°,V _c =444.2 ų,Z=2,D _x =1.80 Mg m^–3, MoK radiation (graphite crystal monochromator, =0.71069 Å),(MoK)=48.58 cm^–1,T=290 K. Final conventionalR-factor=0.037,R _w =0.044 for 1863 observed reflections and 145 variables. The structure was solved usingMultan andDirdif. The results show that the 5-bromo substituent has a marked effect on the geometry of the homocubane skeleton. Its presence prevents a complete release of geometrical strain and induces a shortening of the bond distances to the apex carbon atom.     

Crystal structures of five policyclic compounds related to the natural product forskolin

(3(Z),4,6a,9a,9b)-(±)-3a,4,6a,7,8,9,9a,9b-octahydro-4,7,7, 9b-tetramethyl-3a-[3-(methoxymethyloxy)-3-methyl-1-butenyl]-5H-naphto[1,8-de]-1,3-dioxin-6-one (I), C₂₂H₃₆O₅,M _r=378.51, monoclinic,P2₁/n,a=6.330(1),b=14.576(2),c=22.837(2)Å,=93.04(1)°,V=2104.1(2)ų,Z=4,D _c=1.19 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=832,T=298 K,R=0.054 for 1971 observed reflections; (7a,10a,10b,12)-(±)-7a,9, 10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6,-de][1,3,2]-benzodioxin-11-one (II), C₂₀H₂₉O₄,M _r=334.5, triclinic,P-1,a=10.595(2),b=12.152(1),c=8.073(1)Å,=106.53(1),=105.65(1), =66.29(1)°,V=897.9(2)ų,Z=2,D _c=1.24 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=362,T=298 K,R=0.046 for 2848 observed reflections; (7a,10a,10b,12, 12a)-(±)-7a,9,10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6-de][1,3,2]-benzodioxin-11, 12-diol (III), C₂₀H₃₂O₅ (two molecules in the asymmetric unit),M _r=352.2, triclinic,P-1,a=12.948(3),b=13.615(3),c=12.197(4)Å,=101.16(2),=111.88(2), =69.48(2)°,V=1863.8(9)ų,Z=2,D _C=1.26 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=768,T=298 K,R=0.060 for 4570 observed reflections; 4-acetoxy-4-[[(4a,5,8a)-(±)-hexahydro-4a,6,6-trimethyl-4H-1,3-benzodioxin-4-one]-5-yl]butan-2-one (IV), C₁₇H₂₆O₆,M _r=326.4, monoclinic,P2₁/c,a=10.495(2),b=12.050(2),c=14.216(2)Å,=108.51(1)°,V=1704.8(5)ų,Z=4,D _c=1.27 Mg/m³,(MoK)=0.71069 Å,=0.9 cm^–1,F(000)=704,T=298 K,R=0.049 for2455 observed reflections; (3a,4,5,6,6a,9a,9b)-(±)-4,5-epoxy-decahydro-3, 3a-dihydroxy-2-ethoxy-4,7,7,9b-tetramethyl-naphto-[1,8-bc]-pyran-6-ol-acetate (V), C₂₀H₃₂O₇,M _r=383.5, monoclinic,C2/c,a=10.353(2),b=17.975(3),c=21.188(3)Å,=91.29(1)°,V=3942(1)ų,Z=8,D _c=1.29 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=1664,T=298 K,R=0.051 for 2120 observed reflections. We report here the complete structures of four decalin derivatives (compoundsI, II, III, V) and one related compound (compoundIV) synthetized in order to find an efficient synthetic approach for the natural productforskolin.     

Synthesis and X-ray crystal structure of three polyazamacrocycles having sulfonate pendant groups: Piperazinyl-monomethanesulfonic acid,sodium hydrogen 1,4,7-triazacyclononane-N,N′-di(methanesulfonate) and 1,4,7,10-tetraazacyclododecane-N,N′-di(methanesulfonic acid)

C₅H₁₀N₂O₃S,1, monoclinicC2/c,a=17.545(5),b=6.822(8),c=13.928(2),=108.36(7),Z=8, MoK, =0.7107 Å,=3.56cm^–1,R=0.061,R _w =0.099. C₈H₁₆N₃O₆S₂Na·2H₂O,2, orthorhombicPna2₁,a=17.964(8),b=10.157(1),c=8.263(4),Z=4, MoK, =0.7107 Å,=4.07 cm^–1,R=0.040,R _w =0.043. C₁₀H₂₀N₄O₆S₂·2H₂O,3, monoclinicP2₁/n,a=9.142(9),b=13.576(7),c=14.028(8),=94.096(8),Z=4, MoK, =0.7107 Å,=3.37 cm^–1,R=0.063,R _w =0.074. Compounds1, 2, and3 were prepared from the pH-dependent sulfomethylation of the di- and polyazamacrocycles.     

Complexes of azobisindoles with π-organic acceptors

Complexes of azobisindoles with tetracyanoethylene and tetracyanoquinodimethane were studied by UV-Vis, FT-IR, Raman, NMR and X-ray spectroscopies. FT-IR and Raman spectra, as well as X-ray analysis, gave useful information on the participation of various sites to the association, through analysis of CN and N=N vibrational modes, while UV-Vis and NMR spectra were less helpful. The crystal structure of complexes 1-ethyl-2-phenyl-3-(1-ethyl-2-phenyl-3-azoindole)indole/TCNE,3a and 1,2-diphenyl-3-(1,2-diphenyl-3-azoindole)indole/TCNQ,5b are reported. In the two complexes, the distances between donor and acceptor planes range between 3.4 and 3.5 Å; in3a tetracyanoethylene faces the phenyl ring of the indole, while in5b the superposition of tetracyanoquinodimethane with the donor is negligible. Compound3a,P–1,a=9.504(2),b=9.513(3),c=8.941(2) Å, =97.81(4), =103.38(3), =84.14(2)°,Z=2,D _calc=2.55 g cm^–3; compound5b,P–1,a=12.648(3),b=12.205(2),c=7.263(3) Å, =103.69(2), =91.23(3), =110.61(2)°,Z=2,D _calc=2.53 g cm^–3.     

Studies of systemic acylanilide fungicides. Part IV. Crystal structure and molecular conformation ofN-(2-methoxyacetyl)-N-(2,6-xylyl)-α-amino-γ-butyrolactone

The crystal structure of the title compound (C₁₅H₁₉NO₄, MW 277.3 amu) was determined by three-dimensional X-ray analysis from diffractometer data. Crystal data are: monoclinic,P2₁/n,a=9.600(3) Å,b=11.964(6) Å,c=12.802(4) Å,=101.25(3)°,V=1442.1(16) ų,Z=4;D _x =1.277 Mg m^–3;(MoK)=0.10 mm^–1. FinalR=0.055 for 1686 observed reflections having 2 (MoK)<50° andI>2.5 (I). The compound is isostructural withN-(2-methoxyacetyl)-N-(2,6-xylyl)-3-amino-1,3-oxazolidin-2-one. The dimethylphenyl ring is almost perpendicular to the amidic plane of the molecule (dihedral angle 81.9°); the butyrolactone ring is in the typical envelope conformation.     

Crystal and molecular structure of (exo)-2-methoxycarbonyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C18H20N2O5

The structure of the title compound, C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, monoclinic, space groupP2₁/c,a=13.7850(8),b=8.8951(7),c=15.1603(11) Å, =111.410(6)°,V _c =1730.7 ų,Z=4,D _x =1.322 Mgm^–3. Cu K radiation (graphite crystal monochromator, =1.54178 Å),(Cu K)=7.69 cm^–1. Final conventionalR-factor=0.057,R _w =0.076 for 2160 observed reflections and 271 variables. The structure was solved usingMultan.     

Crystal structure of 4,6-dinitro-1-(5-tetrazolyl)-1H-indazole trihydrate

The title compound, C₈H₄N₈O₄·3H₂O, crystallizes in space groupP¯1 with cell constantsa=7.022(1),b=9.507(2),c=10.906(2) Å,=84.99(1),=71.89(1),=72.56(1)°,Z=2, andV _c =660.2 ų. The structure was solved by direct methods using diffractometer data and was refined by full-matrix least-squares methods to anR value of 0.060 for 2112 observed reflections. The molecule, consisting of a phenyl ring fused to a pyrazole ring with a tetrazole ring connected to it equatorially, is planar except for the N(7) nitro-group oxygen atoms. The structure is stabilized by a three-dimensional network of O-HO, O-HN, and N-HO hydrogen bonds through the water molecules.     

Crystal and molecular structure of (exo)-1-carboxymethyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidmo-[2,3-a]-β-carboline,C18H20N2O5

The structure of the title compound C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, monoclinic, space groupP2₁/c,a=15.589(4),b=7.619(1),c=16.792(4) Å, =111.47(2)°,V=1856.1 ų,Z=4,D _x =1.23 Mg m^–3. CuK radiation (graphite crystal monochromator, =1.54178 Å),(CuK)=7.17 cm^–1,F(000)=728. Final conventionalR-factor=0.075,R _w =0.106 for 2266 observed reflections and 274 variables. The structure was solved usingMultan.     

Two acetylamino derivatives of 2,4-bis(trichloromethyl)-1,3-benzdioxin showing different types of hydrogen bonding: (a) (C13C)CH⋯O=C and (b) N-H⋯O=C

8-Acetylamino-6-methyl-2,4-bis(trichloromethyl)-1,3-benzdioxin, (I), is monoclinic,P2₁/c,a=15.174(4),b=11.977(7),c=9.911(3)Å,=99.72(2)°. 6-Acetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin, (II), is monoclinic,P2₁/_n,a=5.927(4),b=40.623(1),c =7.120(3)Å,=91.39(4)°. In compound (I) the imino hydrogen atom is locked in an intramolecular hydrogen bond to the proximate oxygen atom of the heterocyclic ring and is not available for intermolecular hydrogen bonding. Instead the weakly acidic hydrogen atom [Cl₃C-C(2)]H takes part in a hydrogen bond to the carbonyl oxygen atom in another molecule. In compound (II) a normal intermolecular hydrogen bond of the type N-HO=C occurs. The 6-acetylam-ino group is twisted about the (C_Ar-N) bond such that the angles NHO=C, C_ArH_ArO=C, NHOH_ArC_Ar, at the carbonyl oxygen group total 360° (where NH is in the related molecule). The packing in both compounds takes the form of infinite chains and in compound (II) partial overlap of the aromatic ring and the acetylamino group, with very little offset, also occurs.     

Syntheses and structures of N-phenylmaleimidetriazoles and by-products

The syntheses, properties, and structures of N-phenylmaleimidetriazole derivatives are described. Intermediates and by-products are also discussed. 1b. a = 43.997(7) Å, 5.7610(9) Å, 8.245(1) Å, = 99.339(4), C₂/c; 2a. a = 13.646(4) Å, b = 7.744(2) Å, c = 10.612(3) Å, = 91.979(6), P2₁/c. 3a. a = 22.245(1) Å, b = 22.245(1) Å, 10.010(1) Å, P42/n. 3a. a = 11.727(2) Å, b = 14.075(3) Å, c = 16.080(3) Å, = 105.859(3), = 105.331(3), = 98.187(3), P-1. 3b. a = 8.561(3) Å, b = 14.755(5) Å, c = 22.771(7) Å, = 97.006(5), P2₁/c. 3c. a = 10.500(2) Å, b = 12.189(2) Å, c = 13.040(2) Å, = 109.091(3), = 106.089(3), = 101.022(3), P-1. 8a. a = 16.389(8) Å, b = 5.749(3) Å, c = 19.316(3) Å, = 97.467(9), P2₁/n. 8b. a = 5.822(2) Å, b = 10.114(3) Å, c = 16.705(4) Å, = 84.681(5), = 82.840(5), = 75.769(4), P-1. 9b. a = 11.251(1) Å, 13.335(3) Å, 13.376(3) Å, = 102.456(4), P2₁/n. 9c. a = 15.836(3) Å, b = 8.236(2) Å, c = 5.447(3) Å, = 92.551(3), P2₁/c. 10a. a = 13.177(2) Å, b = 14.597(2) Å, c = 5.5505(8) Å, = 110.979(2), Cc. 11a. a = 14.720(2) Å, b = 13.995(2) Å, c = 38.245(6) Å, = 94.430(3), P2₁/n. 12b. a = 15.067(5) Å, b = 20.378(6) Å, c = 8.669(5) Å, = 99.16(4), = 99.32(3), = 105.23(3), P-1. 13b. a = 8.2824(6) Å, b = 10.5245(7) Å, c = 15.518(1) Å, = 92.305(1), = 100.473(1), = 100.124(1), P-1. 15a. a = 15.357(3) Å, b = 7.778(2) Å, c = 22.957(2) Å, Pbca. 16b. a = 18.0384(4) Å, b = 12.474(3) Å, c = 20.078(5) Å, Pbca.     

Crystal structures of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes

The crystal and molecular structure of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1–5) have been determined by single crystal X-ray diffraction analysis. In all five compounds, the tetraazabicycloundecane portion of the molecule assumes a cage-like, folded structure with the aryltriazene moieties aligned approximately parallel; the structure is held in the folded configuration by either intramolecular or intermolecular – stacking forces. Crystal data: 1 C₁₉H₂₂N₁₀O₄, monoclinic space group P2₁/c, a = 10.1846(7), b = 9.9556(7), c = 20.819(2) Å, = 98.725(1)°, V = 2086.5 (3) ų, Z = 4; 2 C₂₃H₂₈N₈O₄, triclinic, space group P, a = 6.7064(7), b = 12.9662(14), c = 14.054(2) Å, = 94.796(2), = 91.621(2), = 104.836(2)°, V = 1175.7(2) ų, Z = 2; 3 C₁₉H₂₂N₁₀O₄, monoclinic, space group P2₁/c, a = 14.237(2), b = 13.520(2), c = 11.5805(12) Å, = 113.514(2)°, V = 2044.0(4) ų, Z = 4; 4 C₂₁H₂₂N₁₀, monoclinic, space group C2/c, a = 54.247(3), b = 11.5531(7), c = 12.9670(7) Å, = 95.710(1)°, V = 8086.4(8) ų, Z = 16; 5 C₂₅H₃₂N₈ 0₄, monoclinic, space group P2₁/c, a = 10.2908(7), b = 16.5687(12), c = 15.1662(10) Å, = 94,188(1)°, V = 2579.0(3) ų, Z = 4.     

Synthesis and crystal structures of quadruply carboxylate-bridged dimeric lanthanide(III) complexes of betaine

Three dimeric lanthanide(III) complexes, [Eu₂(bet)₈(H₂O)₄](CIO₄)₆ (1), [Tb₂(bet)₈(H₂O)₄](ClO₄)₆ (2), and [Eu₂(bet)₄(H₂O)₈] Cl₆·6H₂O (3) (bet = Me₃N⁺CH₂COO^–, trimethyl-aminoacetate), have been prepared and structurally characterized by X-ray crystallography. Complex 1 crystallizes in the monoclinic space group P2₁/c, with a = 11.7807(8), b = 27.757(5), c = 11.7980(8) Å, = 99.500(4)°, V = 3805.1(8) ų, and Z = 2. Complex 2 is isomorphous to complex 1, crystallizing in the monoclinic space group P2₁/c, with a = 11.7769(14), b = 27.725(3), c = 11.795(5) Å, = 99.668(14)°, V = 3797(2) ų, and Z = 2. Complex 3 crystallizes in the orthorhombic space group Pbca, with a = 12.5664(8), b = 17.8645(9), c = 22.2573(8) Å, V = 4996.6(4) ų and Z = 4. Both complexes 1 and 2 comprise quadruply carboxylate-O,O-bridged [M₂(bet)₄]⁶⁺ dimeric cores (M = Eu, Tb), and each metal ion is further coordinated by two terminal aqua ligands and two monodentate bet carboxylates to form a distorted square-antiprismatic coordination geometry. Complex 3 also has a [Eu₂(bet)₄]⁶⁺ core, in which two bet ligands act in the ¹:¹:₂ bridging fashion, and the other two bet ligands in the less common ²:¹:₂ bridging fashion, namely bridging-chelate mode. Each europium(III) ion in complex 3 is further coordinated by four water molecules to complete a monocapped square antiprism.