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.     

Intramolecular hydrogen bonding and tautomerism in N-(3-pyridil)-2-oxo-1-naphthylidenemethylamine

N-(3-pyridil)-2-oxo-1-naphthylidenemethylamine (C₁₆H₁₂N₂O) was studied by elemental analysis, IR, ¹H NMR, and UV–visible techniques and X-ray diffraction methods. The UV–visible spectrum of the compound was investigated in solutions effect polarity. The polarity of the some solvents was modifierly the additional (CF₃COOH) and [(C₂H₅)₃N]. The compound is in tautomeric equilibrium (phenol-imine O–H···N and keto-amine O···H–N forms) in polar and nonpolar solvents. The keto-amine form is observed in basic solutions of DMSO, ethanol, chloroform, benzene, cyclohexane, and in acidic solutions of chloroform and benzene, but not in acidic solutions of DMSO and ethanol. The compound crystallizes in the monoclinic, space group P2₁/a with a = 7.010(5) Å, b = 13.669(4) Å, c = 12.764(4) Å, = 101.23(4)°, V = 1199.6(10) ų, Z = 4, D _c = 1.375 g/cm³, (Mo K) = 0.088 mm^–1, R = 0.045 for 1658 reflections [I > 2(I)]. The title compound is not planar two Schiff base moieties A [C1–C11, O1] and B [N1, C12, C13, N2, C14, C15, C16] are inclined at an angle of 27.4(1)° reflecting mainly the twist about C12–N1 [C11–C12–N1–C13, 29.7(2)°]. There is a strong intramolecular hydrogen bond (O–H···N) of 2.529(2) Å.     

Aquadifluoro(1,10-phenanthroline)copper(II) dihydrate: X-ray crystal structure reveals strong hydrogen bonds between ligand fluoride and lattice water molecules

C₁₂H₁₄CuF₂N₂O₃,M=335.797, monoclinic, space groupP2₁/n,a=6.985(2),b=17.406(2),c=10.581(2) Å,=92.41(2)°,V=1285(1) ų,D _c =1.736 g cm^–3,Z=4,F(000)=684,(CuK)=27.0 cm^–1, =1.5418 Å,T=20°C, crystal dimensions=0.75×0.45×0.30 mm. The structure of the title compound shows it to be [Cu(phen)F₂(H₂O)]·2H₂O with pentacoordinate-square pyramidal Cu(II), short Cu-F bonds [1.890(4) and 1.891(4) Å], and short FH-O hydrogen bonds (ca. 2.68 Å) between the complex and lattice water molecule.     

Stereochemistry of racemic hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-dienenickel(II) thiocyanate,C16H32N4Ni(SCN)2 · H2O

The diamagnetictrans-diene thiocyanate salt of the macrocyclic hexamethyl-1,4,8,11-tetraazacyclotetradecadienenickel(II) complex crystallizes in the triclinic system with unit cell dimensions:a = 7·334(4),b = 8·808(6),c = 21·04(2) Å; = 63·7(0·9), = 103·8(1·4), = 110·2(1·3) °; space groupP¯1;Z = 2. The positions of all 62 atoms of the formula unit C₁₆H₃₂N₄Ni(SCN)₂.H₂O have been determined and refined by least-squares methods toR= 0·071 for 3536 X-ray diffractometric reflections. The optical activity of the two amine groups yields a racemic isomer. The only local symmetry element of the macrocyclic complex is the twofold rotation axis with the N-H bonds oriented on the same side of the approximate ligand plane. Both the C(CH₃)₂ and the imine groups are in atrans-configuration in the ring. The space group ensures that the crystal is a racemate, containing equal numbers of both enantiomers. One of the (SCN)^– groups is at a distance Ni-S 3·28 Å, the other one is 4·65 Å. No rotational disorder of the CH₃ groups has been observed. The three C-H bonds of the CH₃ groups are in approximately antiprismatic orientations with respect to the three -bonds in the case of bonding to a C(sp³) atom. The average of the C(sp³)-C(sp²) bond lengths is 1·53 Å, and the mean value for the C(sp³)-C(sp²) bonds is 1·50 Å, with 3 = 0·03 to 0·04 Å. The distances N(sp²)-C(sp³) 1·47 Å and 1·48 Å are significantly longer than the bond lengths N(sp²)=C(sp²) of 1·28 and 1·30 Å.     

Heptacoordination in MnII,NiII, and CuII complexes of 2,6-diacetylpyridine bis (acetylhydrazone)

Manganese(II), nickel(II), and copper(II) complexes of 2,6-diacetylpyridine bis (acetylhydrazone) (H₂dapac) have been synthesized and structurally characterized by X-ray diffraction methods. [Mn(H₂dapac) (OH₂)₂](NO₃)₂ crystallizes in the monoclinic space groupP2₁/c witha=11.145(3),b=10.723(4),c=17.189(2) Å, =92.81(2)° andZ=4; [Ni(H₂dapac)(OH₂)₂] (NO₃)₂·H₂O crystallizes in the monoclinic space groupP2₁ witha=9.994(3),b=14.423(4),c=7.697(2)Å, =100.37(2)°, andZ=2; [Cu(H₂dapac)(OH₂)₂](NO₃)₂·H₂O crystallizes in the orthorhombic space groupPbcn witha=20.986(5),b=14.552(3),c=6.905(1)Å andZ=4. In each case the metal atom has a slightly distorted pentagonal bipyramidal environment, the equatorial positions being occupied by three nitrogen and two oxygen atoms from the hydrazone ligand and the apices by two water molecules. The crystalline cohesion in ensured by a three-dimensional network of hydrogen bonds involving the complex cations, the nitrate anions, and, where present, the uncoordinate water molecules.     

Crystal structure of two lipophilic antifolates: 2,4-diamino-5-(n-hexyl)-6-methylpyrimidine and 2,4-diamino-5-(n-heptyl)-6-methylpyrimidine ethanesulfonate

The 5-hexyl (I) and the 5-heptyl (II) analogs of 2,4-diamino-6-methylpyrimidine both crystallize in the space groupP2₁/c withZ=4. Unit cell parameters of I are C₁₁H₂₀N₄·H₂O,a=17.204(3),b=4.609(9),c=16.765(2)Å,= 91.53(2)°; those of II are C₁₂H₂₃N₄ ⁺·C₂H₅SO₃ ^–,a=12.489(1),b=16.702(2),c=8.9558(7)Å,=99.208(8)°. The molecular packing of I contains one water, while II forms a salt with ethanesulfonic acid. The alkyl chain of I adopts an alltrans conformation; in contrast, II has onegauche orientation between carbons 2 and 3 of heptyl. These are the first structural data on two alkyl lipophilic antifolates with antineoplastic activity.     

Crystal and molecular structure of 1-amino-1-methylethylphosphonic acid monohydrate

The crystal and molecular structure of 1-amino-1-methylethylphosphonic acid monohydrate (C₃H₁₀NO₃P·H₂O) has been determined by single-crystal X-ray diffraction methods. The crystals are orthorhombic:Pna2₁,a=11.665(2),b=9.415(1),c=6.386(1) Å,Z=4. The structure was solved by the heavy-atom method and refined to a finalR=0.028. The molecule exists as a zwitterion, H ₃ ⁺ N-C-(CH₃)₂-PO₃₄H^–. There are six independent hydrogen bonds in the structure, three of the type N-HO with lengths 2.904(5), 2.745(6), and 2.765(5) Å and three of the type O-HO with lengths 2.754(4), 2.833 (7), and 2.548(5) Å.     

Diastereoisomers of a prednisolone derivative

The crystal and molecular structures of two synthetic corticosteroid diastereoisomers were determined by X-ray diffraction methods. (22R)-21-acetoxy-16,17-furfurylidenedioxy-11-hydroxy-pregna-1,4-diene-3,20-dione, C₂₈H₃₂O₈, crystallized in the orthorhombic system, space group P2₁2₁2₁,a=6.346(1),b=14.106(2),c=27.901(3) Å, andZ=4. (22S)-21-acetoxy-16, 17-furfurylidenedioxy-11-hydroxy-5 pregna-1,4-diene-3,20-dione ethanolate, C₂₈H₃₂O₈ ·C₂H₅OH, crystallized in the monoclinic system, space group C2,a=20.382(5),b=8.331(1),c=17.346(4)Å, =103.43(2)°, andZ=4. A change of configuration at the C(22) chirality center has influence on the remote parts of the molecules. The long-range effects appear in the ability to form intermolecular hydrogen bonds by different atoms and consequently in the solvation of the (S) diastereoisomer.     

A novel vanadyl selenite templated by organic salt: [(VO)(H2O)2(SeO3)]2[(H2pipe)SO4]

The title compound [(VO)(H₂O)₂(SeO₃)]₂[(H₂pipe)SO₄] was synthesized under hydrothermal condition with VOSO₄, piperazidine (pipe), and SeO₂, and its crystal structure was established using single-crystal X-ray diffraction method. The title compound was characterized with IRFluorescence. The crystal data: P-1 (No. 2), a = 8.633(2) Å, b= 9.223(2) Å, c= 12.508(3) Å, =109.28(3)°, =90.42(3)°, = 107.79(3)°, Mr = 644.08, V=888.5(3) ų, Z=2, Dc = 2.407 g cm^–3, =5.350 mm^–1, F(000)=632. The structure of the title compound consists of an infinite neutral ladder chain, which is built up from VO₆ octahedral and SeO₃ pyramidal units sharing vertices, and organic salt. The biprotonized pipe (piperazidine) and SO₄ ^2– interact with one another and the inorganic chain through strong hydrogen bonds N–H···O or O–H···O to give a 3D structure. Hydrogen bonds play a role of stabilization structure.     

Synthesis and crystal structures of two potential gem-di(pyrazolyl)cycloalkane ligands, 1,1-di(pyrazol-1-yl)cyclohexane [C6H10(C3N2H3)2] and 1,1-di(pyrazol-1-yl)cyclopentane [C5H8(C3N2H3)2]

The species 1,1-di(pyrazol-1-yl)cyclohexane, C₁₂H₁₆N₄, crystallizes in the monoclinic space group P2₁/c with a = 8.340(2), b = 14.281(5), c = 10.153(3) Å, = 106.86(2)°, and Z = 4. The cyclohexane moiety has the chair conformation. The congener, 1,1-di(pyrazol-1-yl)cyclopentane, C₁₁H₁₄N₄, while not isomorphous, also crystallizes in space group P2₁/c with a = 14.350(2), b = 6.776(1), c = 11.043(2) Å, = 100.68(1)°, and Z = 4. The cyclopentane ring has a conformation in which four carbon atoms are essentially coplanar, while the fifth (that with the two pyrazolyl substituents) lies 0.63 Å from this plane, resulting in a bend of 41.3° across the C(2)···C(5) vector. The hydrogen atoms in each structure were located directly and their coordinates refined.     

Hydrogen bonding in 2-hydroxy((di)thio)benzoates. II. X-ray structures of tetraethylammonium salts

X-ray structural data are reported for tetraethylammonium-2-hydroxythiobenzoate (C₁₅H₂₅NO₂S; orthorhombic,Pna2₁(33);a=14.155(2)Å,b=7.651(1)Å,c=14.855(2)Å;Z=4;R=0.038, at 295 K) and for tetraethylammonium-2-hydroxydithiobenzoate (C₁₅H₂₅NOS₂; orthorhombic,Pna2₁(33);a=15.668(4)Å,b=8.729(2)Å,c=12.350(3)Å;Z=4;R=0.031, at 295 K). In both compounds the OH groups are engaged in intramolecular O-HS hydrogen bonds (OS=2.88 and 2.89 Å, respectively).     

Refinements of the crystal structures of 1,4-diphenylbutadiyne and its complex with two moles of Co2(CO)6

1,4-diphenylbutadiyne, C₁₆H₁₀, crystallizes in monoclinic space group P2₁/n witha=6.6152(6),b=6.0768(7),c=14.634(1) Å, =100.981(8)⁰,V=577.5(2) ų,Z=2. The structure was refined toR=0.077 andR _w=0.069 for 1007 observed reflections with CuK radiation. The molecule lies on an inversion center. Our determination represents and increase in precision of a factor of approximately three over the original determination. The 21 cobalt complex, C₁₆H₁₀[Co₂(CO)₆]₂, also crystallizes in monoclinic space group P2₁/n witha=8.9568(12),b=17.7057(10),c=18.5671(12) Å, =90.606(12)^o,V=2944.3(5) ų,Z=4. The structure was refined toR=0.032 andR _w=0.031 for 4312 observed reflections. The diphenylbutadiyne triple bonds elongate to 1.346(3) Å and the angles at the diyne C atoms decrease to 134.1(3)–144.9(3)^o upon complexation. The Co-Co distance is 2.4580(4)Å. Our data represent an increase in precision by a factor of 2–3 over the original determination.     

Crystal structures of thetrans-cyclooctene complexes of copper(I) chloride and silver nitrate

The crystal and molecular structures of the title compounds CuCl·C₈H₁₄ and AgNO₃·C₈H₁₄, have been determined by single-crystal X-ray diffraction techniques, and refined by full-matrix least squares. Both compounds crystallize in the orthorhombic space groupPbca witha=6.191(7),b=12.456(2),c=23.272(4) Å for CuCl·C₈H₁₄, anda=7.383(2),b=9.825(2),c=26.980(5) Å for AgNO₃·C₈H₁₄;Z=8 in both cases. FinalR factors are 0.047 and 0.029 respectively. The cyclooctene ring has the twist chair-chair (TCC) conformation, with approximateD ₂ symmetry, in both compounds, and the torsion angles around the double bonds are –134.2(4) and –137.0(4)° respectively. Slight lengthening of the metal-complexed double bond is attributed to enhanced olefin metal -donation of thetrans bond.     

Crystal structure and spectroscopic properties of glycinium monophenylphosphate

The crystal structure of glycinium monophenylphosphate [NHsk3/+CH₂COOH·C₆H₅OPO₃H^– has been determined. The crystals are orthorhohombic:Pbca (NO. 61),a=26.001(3),b=7.423(2),c=11.273(2) Å,Z=8. The structure was solved by direct methods, are refined toR=0.035 for 1499 independent reflections. The crystal structure is stabilized by a three-dimensional network of hydrogen bonds. The phosphate group is involved in five H bonds: three NO and two OO bonds, with the shortest distances 2.745(3) and 2.608(2) Å, respectively. The glycine cation is entirely planar, and a cationo-anionic form of the title compound has also been confirmed in solution byIR studies.     

Molecular distortions in crystalline 2-phenylethynylbenzoic acid

2-Phenylethynylbenzoic acid shows a short intramolecular 1,5 C=O···spC contact with no significant in-plane distortion of bonding geometry at the sp C atom. However, there are angular distortions at the second sp C atom and the adjacent ipso C atom of the benzene ring, most likely because of optimization of the packing arrangement. Crystal data: C₁₅H₁₀O₂, Mr = 222.23, a = 6.1890(10), b = 9.791(2), c = 18.849(4) Å, = 97.14(2)°, monoclinic, P2₁/n, Z = 4.     

Molecular structure and hydrogen bonding of 4-dimethylaminopyridinioacetate in its crystalline dihydrate and hydrochloride trihydrate,L·2H2O and [L2H]Cl·3H2O (L=p-Me2NC5H4N+CH2CO2 −)

The crystalline dihydrate and hydrochloride trihydrate of a new betaine, namely, L·2H₂O (1) and [L₂H]Cl·3H₂O(2) (L=p-Me₂NC₅H₄N⁺CH₂CO₂), have been synthesized and characterized by X-ray crystallography. Molecule L in compound1 [space groupPbcn, witha=15.732(3),b=7.894(2),c=18.304(4) Å, andZ=8] possesses approximateC _s symmetry. The formation of hydrogen bonds by water molecules bridging neighboring carboxy oxygen atoms leads to an infinite two-dimensional network composed of a packing of two different kinds of 12-membered rings. In compound2 [space group PT witha=7.341(2),b=9.543(2),c=17.010(4) Å, =82.43(2)°, =80.34(2)°, =74.05(2)°, andZ=2], the carboxylate groups of a pair of betaine molecules are bridged by a proton to form a dimeric cation L₂H⁺ with a very strong asymmetric hydrogen bond of length 2.464(7) Å. The crystal structure features a hydrogen-bonded corrugated ribbon comprising an alternate arrangement of edge-sharing centrosymmetric (H₂O)₄(Cl^–)₂ and (H₂O)₄ rings running parallel to thea axis.     

Di-2-pyridylketone semicarbazone as ligand in metal complexes: synthesis and X-ray crystal structure

A series of complexes of di-2-pyridylketone semicarbazone (Hdips) and Mn(II), Co(II), Co(III), Ni(II) and Cu(II) nitrates were synthesized and characterized by means of IR spectroscopy and for cobalt and nickel by X-ray crystal structures. The results are in agreement with the formulae: Mn(Hdips)₂(NO₃)₂·2H₂O, [Co(Hdips)₂](NO₃)₂·H₂O (I), [Ni(Hdips)₂](NO₃)₂·H₂O (II), Cu(Hdips)(NO₃)₂·2H₂O, [Co(dips)₂](NO₃)·2H₂O (III). The structure of I and II are monoclinic, space groupP2₁/c, with, I,a=15.980(4),b=11.531(2),c=16.170(2)Å;=104.20(2)°,Z=4,R=0.032; II,a=16.109(5),b=11.480(3),c=16.135(6)Å;=104.15(2)°,Z=4,R=0.069. Compound III is also monoclinic, space groupP2₁/c witha=12.173(5),b=15.619(5),c=15.338(8)Å;=111.40(4)°,Z=4,R=0.059. In these complexes the ligand is tridentate via carbonylic oxygen, semicarbazone and pyridine nitrogens forming each two five membered chelate rings with the metal in a distorted octahedral geometry.     

The crystal structure of 2-amino-5,5′-bis(β-cyanoethyl)-1,2-pyrrolenineN-oxide monohydrate

2-Amino-5,5-di(-cyanoethyl)-1,2-pyrrolenineN-oxide monohydrate, C₁₀H₁₄N₄O·H₂O, crystallizes from MeCN in space group P2₁2₁2₁ witha=7.0007(5),b=8.2998(6),c=20.8418(13) Å,V=1211.0(2) ų,Z=4. The structure was refined toR=0.034 andR _w=0.044 for 2325 observed reflections. The pyrrolenine ring adopts a nearly planar conformation, with maximum deviation from planarity 0.089(2) Å. The N–O distance is 1.345(2) Å. The water molecule bridges two pyrrolenine molecules via hydrogen bonds to theirN-oxide oxygen atoms, and also accepts a hydrogen bond from the NH₂ group of another pyrrolenine molecule.     

Influence of the spectator cation on the structure of anionic pyridine-2,6-dicarboxylato complexes of cobalt(II), nickel(II), and copper(II)

The structures of anionic pyridine-2,6-dicarboxylato (pdc^2–) complexes of cobalt, nickel, and copper have been studied. The stoichiometries and structures are very much dependent on whether KOH, Et₄NOH, or NaOH is used in the synthesis to deprotonate the H₂pdc ligand. Crystallographic results are: (1) K₂[Co(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.637(2)Å, b = 13.480(1)Å, c = 8.200(1)Å (2) K₂[Ni(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.648(1)Å, b = 13.375(1)Å, c = 8.2393(8)Å (3) [Co₂(H₂O)₅(pdc)₂] · 2H₂O, monoclinic, P2₁/c, Z = 4, a = 8.3880(6)Å, b = 27.384(2)Å, c = 9.6110(8)Å, = 98.271(6)° (4) [Ni(Hpdc)₂] · 3H₂O, monoclinic, P2₁/c, Z = 4, a = 13.679(1)Å, b = 10.0450(9)Å, c = 13.767(2)Å, = 115.184(7)° (5) Na₆[Co(H₂O)₆][Co(pdc)₂]₄ · 28H₂O, monoclinic, P2₁/n, Z = 2, a = 13.363(1)Å, b = 8.437(1)Å, c = 40.689(3)Å, = 91.288(5)° (6) Na[Ni(Hpdc)(pdc)] · 11.5H₂O, monoclinic, C2/m, Z = 4, a = 15.200(2)Å, b = 22.299(2)Å, c = 8.3596(7)Å, = 118.894(7)° (7) Na[Cu(Hpdc)(pdc)] · 3H₂O, monoclinic, P2₁/n, Z = 4, a = 9.516(4)Å, b = 14.917(6)Å, c = 12.247(5)Å, = 92.00(5)°. The potassium and sodium complexes have extensive K⁺—H₂O and Na⁺—H₂O networks. The fact the Et₄N⁺ ion does not appear in any of the complexes is likely due to the fact that it is incapable of forming the intricate cation—water and hydrogen-bonding networks observed in all of the other structures.     

Crystal structure of tolazoline hydrochloride

The title compound (C₁₀H₁₂N₂ HC1,M _r =196.7) crystallizes in the monoclinic space groupP2₁/c witha=8.997(1),b=9.665(1) andc=12.290(1) Å,=104.41(1)°,V=1035·1 ų,D _x =1.262 g·cm^–3 forZ=4,=29.4 cm^–1, (CuK)=1.54178 Å,F(000)=416. FinalR=0.051 (R _w =0.063) for 1937 reflections collected on a diffractometer. The structure was solved by direct methods. The two N atoms of the imidazoline ring are equivalent due to protonation and they participate in N-HCl hydrogen bonds which join the molecules into infinite chains. The imidazoline ring is approximately planar and is oriented perpendicular to the plane of the benzene ring. The separations of the two N atoms from the center of the aromatic ring are 4.691(3) and 4.598(3) Å, close to the values found in the crystal structures of clonidinelike agents.