Structural characterization of Elisabatin B and Elisabatin C

X-ray structures of Elisabatin B (1) and Elisabatin C (2) have been determined. Crystal data for 1: Triclinic, P (No. 2), a = 7.528(2) Å, b = 9.404(2) Å, c = 11.414(2) Å, = 75.363(3)°, = 86.668(4)°, = 89.683(4)°, and Z = 2. Crystal data for 2: Monoclinic, P2₁/c (No. 14), a = 8.242(2) Å, b = 14.870(2) Å, c = 13.060(2) Å, = 101.458(3)°, and Z = 4. Both compounds are highly unsaturated leading to extended aromatic conjugation. They show different intermolecular O–HO hydrogen bonds, via which 1 forms dimers, and 2 zig-zag polymeric chains.     

Novel manganese(III) oxidation chemistry: X-ray crystal structures of (1α,2α,4β)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-1,2,3,4-tetrahydronaphthalene (compound A) and (1α,2α,4β)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-1,2,3,4-tetrahydronaphthalene (compound B)

CompoundA is (1,2,4)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, monoclinic, P2₁/n, witha=11.074(3),b=10.353(4),c=17.616(4)Å,=94.96(2)°,V=2012.1ų,D _calc=1.27 g cm^–3 and=0.55 cm^–1 forZ=4. Least-squares refinement of 1371 observed [F ₀5 (F ⁰)] reflections led to the final agreement index ofR=0.052. A twofold disorder was observed for the 1-acetoxy group whereas the 2-acetoxy group was ordered. CompoundB, (1,2,4)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, crystallizes in the monoclinic space group, P2₁/c, witha=16.209(2),b=10.076(1),c=13.357(4)Å,=111.41(2)°,V=2030.9ų,D _calc=1.26 g cm^–3 and=0.54 cm^–1 forZ=4. A final agreement index ofR=0.045 was realized by least-squares refinement of 1486 observed [F _o5 (F _o)] reflections. Intermolecular interactions in the cell lattices of compoundsA andB are noted. The title compoundsA andB were prepared by manganese(III) acetate oxidative dimerization of two molecules of 4-methoxystyrene and 2-methoxystyrene, respectively.     

Cyclohexanone inclusion compounds of related multipedal hosts

The structures of the cyclohexanone inclusion compounds of (1) hexakis (3-hydroxy-3, 3-diphenyl-2-propynyl) benzene (H1) (triclinic, P1¯, a = 8.957(4), b = 16.69(1), c = 17.201(4) Å, = 93.82(3), = 97.61(3), and = 93.13(5)°); (2) 1,2,3,5,6,7-hexakis(3-hydroxy-3,3-diphenyl-2-propynyl)naphthalene (H2) (monoclinic, P2₁/n, a = 9.444(5), b = 18.353(5), c = 31.59(1) Å, and = 92.18(3)°) and (3) tetra(3-hydroxy-3,3-diphenyl-2-propynyl)ethylene (H3) (triclinic, P1¯, a = 14.208(2), b = 14.710(4), c = 17.915(2) Å, = 91.06(1), = 89.98(1), and = 110.60(2)°) have been determined. A second cyclohexanone inclusion compound with H1 with a different host to guest ratio (4: triclinic, P1¯, a = 9.512(2), b = 15.327(3),c = 16.151(3) Å, = 114.89(2), = 95.19(2), and = 102.67(2)°) was obtained from a 50:50 molar solution of cyclohexanone and 1,4-dioxane, which confirms the selectivity of this host for compounds with carbonyl functional groups. The thermal analysis results of all these cyclohexanone inclusion compounds are reported.     

Crystal structures of 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione and 1-(1,3-benzodioxol-5-yl)-3-(2,4-dimethoxyphenyl)-1,3-propanedione

1-(2-Hydroxyphenyl)-3-phenyl-1,3-propanedione crystallizes in the triclinic space group (a=5.4233(5),b=13.910(1),c=17.036(1) Å, =68.311(6), =80.854(7), =78.760(8)°) as two independent enolic tautomers in which the hydroxyl and phenolic protons are hydrogen bonded to the ketonic oxygen atom. The structure was refined toR=0.039 for 2085I3(I) reflections. 1-(1,3-Benzodioxol-5-yl)-3-(2,4-dimethoxyphenyl)-1,3-propanedione, which belongs to the triclinic space group (a=7.3990(7),b=8.1239(5),c=14.004(1) Å, =86.673(6). =88.574(7), =64.885(7)°) also exists in the enolic form. The structure was refined toR=0.040 for 1564I3(I) reflections.     

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.     

Crystal structures and energy refinement of some 2,2′-disubstituted biphenyl compounds

Synthesis and structural determination by X-ray crystallography of three substituted biphenyl structures are reported: (2) is monoclinic P2₁/n witha=10.805(4),b=8.079(3),c=16.232(6)Å, =100.96(5)°: (4) is monoclinic P2₁/n witha=9.966(3),b=10.007(3),c=13.053(4) Å, =96.74(5)°; (5) is triclinic witha=12.033(5),b=16.903(8),c=9.752(4)Å, =94.70(3)°, =112.56(3)° =76.12(3)°. In all compounds the biphenyl has two identical substituents in an ortho position to the center inter-ring bond and present variable inter-ring twist angles. In the process of investigating molecular geometry, we are interested in studying whether the calculated conformations of our molecules can fit the crystallographic structures.     

Synthesis and crystal structures of 4,4′-bipyridinium and 2,2′-bipyridinium pentachloro complexes containing the polynuclear anions [Bi2Cl10]4− and [Bi4Cl20]8−

The compounds 4,4-bipyridinium(2+) pentachloro-bismuthate(III) (1), [4,4-(C₁₀H₈N₂)BiCl₅] and 2,2-bipyridinium(2+) pentachloro-bismuthate(III) (2), [2,2-(C₁₀H₈N₂)Bi₂Cl₁₀] have been obtained by reacting bismuthate oxide and 4,4-bipyridine or 2,2-bipyridine in HCl acid medium. They have been characterized by single crystal X-ray analysis. (1) crystallizes in the triclinic space group with a = 9.776(2), b = 11.009(3),c = 8.346(1) Å, = 101.58(2), = 98.63(2), and = 112.86(2)°. (2) crystallizes in the monoclinic space group P2₁/c with a = 14.239(2), b = 14.226(2), c = 16.275(3) Å, and = 110.15(2)°. The crystal structure of (1) consists of 4,4-bipyridinium(2+) cations interacting through hydrogen bonding with [Bi₂Cl₁₀]^2– dimers giving rise to endless double chains, while that of (2) is formed by 2,2-bipyridinium(2+) cations and [Bi₄Cl₂₀]^8– tetramers extensively interacting through hydrogen bonding. The different polynuclearity of the anions seems related to the different directions along which each cation can form hydrogen bond interactions.     

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.     

Synthesis and crystal structure of bis(2,2′-bipyridyl)mononitritozinc(II) perchlorate. An example of a six-coordinate cis-octahedral ZnN4O2 chromophore

The crystal structure of bis(2,2-bipyridyl)mononitritozinc(II) perchlorate, [Zn(bipy)₂ (ONO)][ClO₄] (1) has been determined. The complex is monoclinic, with a = 10.9195(4) Å, b = 12.2320(5) Å, c = 16.5477(8) Å, = 105.6150(10), P2₁/n space group, with final R1 = 0.0657 and wR2 = 0.1630. The complex involves a [Zn(bipy)₂ (ONO)]⁺ cation and a [ClO₄]^– anion. The ZnN₄O₂ chromophore is six-coordinate, with a cis-distortion of the two oxygens of the nitrite, O(1) and O(2), at distances 2.216(5) and 2.197(5) Å from the zinc (Zn– O _mean = 2.206(5) Å, O = 0.019(5) Å) and two out of plane Zn–N bonds, Zn–N(2) and Zn–N(3), at 2.129(4) and 2.135(4) Å (Zn–n _mean/out = 2.132(4) Å, n _2,3 = 0.006(4) Å). The two inplane nitrogens, N(1) and N(4), at distances Zn–N(1) = 2.090(4) and Zn–N(4) = 2.085(4) Å (Zn–n _mean/in = 2.087(4) Å, n _1,4 = 0.005(4) Å) are greater than 2.0 Å, but slightly shorter than the axial bonds. The inplane angles ₁, ₂, and ₃ in 1 have values 150.33(18), 108.98(17), and 99.73(18) respectively. The stereochemistry is cis-distorted octahedral, with an ₃ = 99.37(18), which is lower than ₃ = 103.4(1) observed in [Zn(bipy)₂(ONO)][NO₃] (5). Comparison with the corresponding [Cu(bipy)₂(ONO)][Y] complexes suggested that the cis-distortion of the CuN₄O₂ chromophore in the copper(II) series does not originate in the Jahn–Teller or pseudo-Jahn–Teller effect.     

Crystal structures of isomorphous cadmium(II) and lead(II) oxalate trihydrates

The isomorphous cadmium(II) oxalate trihydrate (I) and lead(II) oxalate trihydrate (II) crystals belong to space groupP¯1 withZ=2. The crystallographic parameters for compoundI are:a=6.006(1),b=6.663(1),c=8.497(1)Å,a=74.76(1),=74.39(1), =80.94(1)°, andR=0.028 for 2643 observed MoK reflections; forII:a=6.008(1),b=6.671(1),c=8.493(1)Å,a=74.70(1),=74.33(1), =80.98(1)°, andR=0.065 for 4536 reflections. In the crystal structure, the metal atom is surrounded by seven oxygen atoms (including two aqua ligands) in the form of a distorted pentagonal bipyramid. The coordination polyhedra are interconnected through bridging oxalate groups to form a thick layer matching the (020) plane. Adjacent layers are further linked by hydrogen bonds involving both ligand and lattice water molecules to generate a three-dimensional network.On leave from Central Laboratory, Nankai University, Tianjin, China.     

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.     

Structure of bis(2-amino-5-methylpyridinium) tetrachlorozincate at 298 and 150 K

Reaction of 2-amino-5-methylpyridine with zinc chloride and HCl in aqueous solution yields bis(2-amino-5-methylpyridinium) tetrachlorozincate. The complex crystallizes in the monoclinic space group P2₁/c, with minimal tetrahedral distortion of the ZnCl₄ ^2– ion at both 298 and 150 K; at 298 K, a = 8.090(2) Å, b = 14.795(6) Å, c = 15.850(4) Å, = 101.93 (2); at 150 K, a = 8.0986(2) Å, b = 14.7190(5) Å, c = 15.7684(7) Å, = 102.862(2). The anisotropic cell contraction results in significant changes in nonbonding Cl Cl contacts.     

A comparison of the coordination preferences of Zn, Co, and Cd(II) with the heteroscorpionate ligand (2-hydroxy-3-t-butyl-methylphenyl)bis (3,5-dimethylpyrazolyl)methane

Reaction of the Zn, Cd, or Co nitrate salts with the deprotonated ligand (2-hydroxy-3-t-butyl-methylphenyl)bis(3,5-dimethylpyrazolyl)methane (L1O^–) in methanol produced the following complexes: [(L1OH)Zn(NO₃)₂] in two isomorphs, a = 40.983(8) Å, b = 9.571(2) Å, c = 15.667(8) Å, = 90, = 106.38(1), = 90, C2/c, and a = 13.027(3) Å, b = 14.781(4) Å, c = 16.107(3) Å, = 90, = 105.30(1), = 90, P2₁/n; [(L1OH)Cd(pz)(NO₃)₂] a = 14.7476(2) Å, b = 13.5411(2) Å, c = 16.7223(2) Å, = 90, = 110.3840(10), = 90, P2₁/c; and [(L1O)Co(pz)(NO₃)] a = 11.4240(2) Å, b = 13.4498(2) Å, c = 13.8056(2) Å, = 105.2080(10), = 105.8130(10), = 112.7470(10), P . The Zn adopts a pseudotetrahedral four-coordinate geometry where the potentially tridentate ligand is actually bidentate with a protonated and uncoordinated phenoxy arm. The Co complex is pseudooctahedral six-coordinate where the phenoxy arm is deprotonated and coordinated. Finally the Cd complex is seven-coordinate but the metal is not coordinated through the phenoxy group that is again protonated.     

Crystal structure of chlorotriphenyltin·diphenylcyclopropenone

Triphenyltin chloride forms with diphenylcyclopropenone a 1/1 molecular complex belonging to the triclinicP¯1 space group (a=10.267(4),b=12.095(2),c=12.319(3)Å,=90.67(2),=101.59(2), =112.58(2)°). The tin atom exists in a distortedtrans-trigonal bipyramidal (Sn-C=2.112(3), 2.123(3), 2.137(4), Sn-C1=2.440(1), Sn-O=2.510(2)Å) geometry, being displaced out of the equatorial plane (EC-Sn-C=354.3(3)°) towards the apical chlorine atom by 0.269(1)Å.     

Synthesis and structure of 4,7,13,16-tetraoxa-1,10-diaza-5,6-benzocyclooctadeca-11,18-dione monohydrate

4,7,13,16-tetraoxa-1,10-diaza-5,6-benzocyclooctadeca-11,18-dione, C₁₆H₂₂N₂O₆·H₂O, (3) was synthesized under thermal conditions, starting from ,-diamine (1) and ,-diester (2). The hydrate of compound (3) was investigated in the solid state by X-ray structural analysis. Crystal data: monoclinic system, space group P2₁/c,a=12.342(4) Å,b=15.978(7) Å,c=8.960(3) Å, =96.72(3)°,Z=4. The structure was solved by direct methods and refined to finalR=0.056,R _w=0.069 for 1962 observed reflections. The structure exhibits internal hydrogen bonds between the etheral O(16) atom and the neighboring amide group. The water molecule connects diamide molecules by one strong hydrogen bond with carbonyl oxygen, and four weak hydrogen bonds with the amide groups and etheral oxygen atoms.     

Crystal structures of bis-11-aminoundecanoic chlorocuprate and bis-11-aminoundecanoic-Cu(II) sulfate trihydrate

Bis-11-aminoundecanoic chlorocuprate: (I),M _r =609.5, triclinic,P¯1 (No. 2),a=7.237(1),b=7.536(1),c=27.605(2) Å, =97.98(8),=92.45(8), =90.02(8)°,V _c =1492 ų,Z=2,D _x =1.357 g cm^–3,D _m =1.35(1) g cm^–3 (flotation), =43.85 cm^–1, CuK radiation=1.5418 Å,F(000)=642,T=23 °C,R=0.065 for 4121 observed reflections. Bis-11-aminoun-decanoic sulfate Cu(II) trihydrate: (II),M _r =616.4, triclinic,P¯1,a=7.745(2),b=9.553(4),c=20.343(5) Å, =80.91(3),=79.28(2), =87.58(3)°,V _c =1460 ų,Z=2,D _x =1.40(1) g cm^–3,D _m =1.38(2) g cm^–3 (flotation),=8.16 cm^–1, MoK radiation=0.71069 Å,F(000)=658,T=23°C,R=0.064 for 3384 observed reflections. In (I) the two copper ions are in special positions 0, 0, 0 and 1/2, 1/2, 0 octahedrally coordinated to Cl^–. The CuCl ₂ ^2– ions make square planes with the short bonds of mean values 2.289 and 2.295 Å. The carbonyls are hydrogen bonded, and the conformation of the amino acid chains ist for whole chain except at C(11) of chainA and N of chainB where it isg. In (II) Cu²⁺ shows a very distorted octahedral coordination with a mean value of 1.959 Å for the short bonds Cu-O and 2.512 Å for the long bonds. TheB amino acid chain presents a similar conformation change at C(11) as in theA chain of complex (I).     

Crystal structures of baclofen analogs: 3-thienyl- and 3-furylaminobutyric acids

X-ray crystal structures of 4-amino-3-(2-thienyl) butyric acid (compound1), 4-amino-3-(4-bromo-2-thienyl) butyric acid (compound2), and 4-amino-3-(5-methyl-2-furyl) butyric acid (compound3) are reported. Space groups and unit/cell parameters are: compound1, monoclinic,P2₁ c,a=13.288(3),b=5.231(1),c=12.388(2)Å,=92.3(1)°; compound2, monoclinic,P2₁/c,a=12.610(7),b=5.156(1),c=15.814(8)Å,=101.8(1)°; compound3, orthorhombic, Pccn,a=11.461(1),b=25.284(2),c=6.977(1)Å. FinalR indices are: compound1, 0.057; compound2, 0.069; compound3, 0.060. Conformations of their -aminobutyric chains are compared with the one of -amino--(p-chlorophenyl)-butyric acid (baclofen, compound4). Two different types of conformations are observed, i.e., conformations (i) with folding (compound3) or (ii) without folding (compounds1,2, and4) of the ammonium group toward the heteroaromatic or aromatic ring. However, distances between ionized groups are constant.     

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).     

Preparation,spectral studies,and X-ray crystal structures of (16S, 17R, 20S)-3-oxo-16-hydroxy-25-nor-lanostan-24-oic lactone (II) and (16S, 17R, 20S)-4,16-dihydroxy-25-nor-3,4-seco-lanostan-3,24-dioic acid dilactone (III)

The crystal and molecular structures of the title compounds have been determined by direct methods, and refined to a finalR of 0.059 forII and 0.046 forIII. Both molecules crystallize in space group P2₁2₁2₁. The cell dimensions forII area=10.096(5),b=11.255(3),c=20.300(7) Å;Z=4,D _x=1.188 g cm^–3, (MoK)=0.70 cm^–1, while the cell dimensions forIII area=7.346(1),b=10.470(3),c=30.546(5) Å;Z=4,D _x=1.212 g cm^–3, (MoK)=0.74 cm^–1. The rings of the triterpene skeletons aretrans-cis-trans-cis connected. The conformations of both molecules are discussed. Also the preparation and the spectral data of (17R, 20S)-3,16-dioxo-25-nor-lanostan-24-oic acid (V) and (17R, 20S)-3,16,24-trioxo-25-hydroxy-16,24-seco-lanostan-25-acetate (VI) are given.