Methoxyflavone Inhibitors of Cytochrome P450

Abstract  Cytochrome P450 enzymes are a superfamily of enzymes involved in the metabolism of endogenous compounds as well as xenobiotics. Due to the large number of reactions catalyzed by these enzymes and their importance in drug metabolism and carcinogenesis, they have been the focus of many studies over the years. Based on the knowledge that flavones are natural substrates of certain P450 enzymes (such as P450 1A2) involved in carcinogenesis, we have synthesized and studied a number of flavonoids as potential inhibitors of these enzymes. These compounds are structurally very similar to the natural flavone substrates of these enzymes but have methoxy substituents at various positions. Here we are reporting the synthesis, structural analysis, X-ray crystal structures, and preliminary inhibition studies of four methoxyflavones from this series. Crystallographic data: 2′-methoxyflavone, P-1, a = 7.2994(8) ?, b = 8.3322(7) ?, c = 10.8240(10) ?, α = 97.905(8)°, β = 92.779(10)°, γ = 111.105(8)°, V = 604.9(1) ?³; 3′-methoxyflavone, P2₁/n, a = 15.1313(16) ?, b = 3.9699(4) ?, c = 19.9454(16) ?, β = 91.673(8)°, V = 1197.6(2) ?³; 4′-methoxyflavone, P2₁/n, a = 16.451(12) ?, b = 3.881(1) ?, c = 19.529(16) ?, β = 106.65(1)°, V = 1195.1(4) ?³; 3′,4′-dimethoxyflavone, C2/c, a = 30.819(5) ?, b = 4.0857(7) ?, c = 26.100(3) ?, β = 124.21(1)°, V = 2717.6(7) ?³. Index Abstract  Methoxyflavone Inhibitors of Cytochrome P450 Michael McKendall, Tasha Smith, Kien Anh, Jamie Ellis, Terri McGee, Maryam Foroozesh, Naijue Zhu and Cheryl L. Klein Stevens* This paper is a report of the synthesis, structural analysis, X-ray crystal structures, and preliminary inhibition studies of 2′-methoxyflavone, 3′-methoxyflavone, 4′-methoxyflavone, and 3′,4′-dimethoxyflavone.

Study of Hydrogen Bonding in <Emphasis Type="Italic">N</Emphasis>′-(4,6-disubstituted-pyrimidin-2-yl)-<Emphasis Type="Italic">N</Emphasis>-[2-(2,4-dichlorophenoxypropionyl)]thiourea

Abstract  

Two of N′-N′-(4,6-disubstituted-pyrimidin-2-yl)-N-[2-(2,4-dichlorophenoxypropionyl)]thiourea (4a-4b) had been synthesized and their crystal structures had been determined by X-ray diffraction method. 4a crystallizes in the triclinic space group P-1, with a = 8.053(12) ?, α = 102.84(2)°, b = 10.541(16) ?, β = 106.99(2)°, c = 12.461(19) ?, γ = 94.615(19)°, and D _c  = 1.470 mg/m³ for Z = 2. 4b crystallizes in the triclinic space group P-1, with a = 7.939(5) ?, α = 105.302(10)°, b = 10.183(7) ?, β = 105.729(9)°, c = 12.764(9) ?, γ = 90.698(11)°, and D _c  = 1.517 mg/m³ for Z = 2.     

Interesting Reactivity in the Thermolysis and Photolysis of 2,3-Diphenyl-1-naphthol

Abstract  2,3-Diphenyl-1-naphthol (1) undergoes two unexpected reactions under different conditions. Compound (1) was heated in DMSO-d₆ and underwent a Pummerer type thermal reaction to give two isomeric products, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d₅ which crystallized in the space group with a = 7.1610(9) ?, b = 11.2795(15) ?, c = 12.8905(17) ?, α = 114.049(2)°, β = 96.589(2)°, and γ = 102.945(2)°, and 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d₅ which crystallized in the space group with a = 8.5981(5) ?, b = 10.4374(6) ?, c = 11.1078(6) ?, α = 78.748(2)°, β = 67.709(2)°, and γ = 83.184(2)°. Photolysis (254 nm) of (1) resulted in 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol which crystallized in the space group P2₁/c with a = 26.3616(11) ?, b = 10.1707(4) ?, c = 23.3376(9) ?, and β = 99.034(2)°. Graphical Abstract  When 2,3-diphenyl-1-naphthol was heated in DMSO-d₆ two unexpected isomers, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d₅ and the racemate 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d₅ were produced. Photolysis in THF at 254 nm led to the unexpected product 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol. All structures were elucidated by X-ray crystallography.      

Synthesis and Characterization of Aplysinopsin Analogs

Abstract  Three aplysinopsin analogs were synthesized by reacting 5-bromo-5-fluoro- and 6-bromoindole-3-carboxaldehyde with either creatinine or 2-imino-1,3-dimethyl-imidazolidin-4-one or 2-imino-1-methyl-3-ethylimidazolidin-4-one Single crystal structures on 5-bromo-4′-de-N-methylaplysinopsin DMF solvate [from creatinine, space group P2₁/n, lattice parameters a = 13.117(3) ?, b = 8.6663(15) ?, c = 14.743(3) ?, β = 99.538(10)° at 173 K], 5-fluoroaplysinopsin DMF solvate [from 2-imino-1,3-dimethyl-imidazolidin-4-one, space group P2₁/c, lattice parameters a = 11.114(3) ?, b = 19.118(2) ?, c = 8.503(2) ?, β = 112.290(7)°], and 6-bromoindole-3-carboxaldehyde (space group P2₁/n, lattice parameters a = 7.657(2) ?, b = 7.933(2) ?, c = 13.521(3) ?, β = 99.046(13)°) have been determined. Characterizations include spectrometric identifications employing IR, UV, HRMS, and ¹H and ¹³C NMR. 5-Bromo-4′-de-N-methylaplysinopsin and 5-fluoroaplysinopsin exist in the E configuration. Index Abstract  Single crystal X-ray structural analyses were carried out on 5-bromo-4′-de-N-methylaplysinopsin, 5-fluoroaplysinopsin, and 6-bromoindole-3-carboxaldehyde.      

Synthesis and Crystal Structure of an Iodobismuthate Incorporating Both a Cationic and Anionic Bi (III) Complex Ion

Abstract  

A new iodobismuthate of formula [BiI₂(terpy)₂][BiI₄(terpy)] (terpy = 2,2′:6′,2′′-terpyridine), was prepared solvothermally in an ethanolic mixture composed of bismuth (III) iodide, terpy, and ruthenium (III) iodide. The compound crystallizes in the space group P [`1] \bar{1} , with Z = 2, a = 9.8491(4) ?, b = 15.4181(7) ?, c = 17.5323(8) ?, α = 89.8140(10)°, β = 80.4160(10)°, γ = 77.9020(10)°. Single-crystal X-ray analysis reveals that the compound is composed of a [BiI₂(terpy)₂]⁺ cation and a [BiI₄(terpy)]⁻ anion. It is an uncommon example where an iodobismuthate cation and anion are simultaneously incorporated into the same crystal structure.     

Synthesis and Crystal Structures of Dioxomolybdenum(VI) Complexes with ONS-Donor Ligands

Abstract  

Three dioxomolybdenum complexes namely dioxo(5-chlorosalicylaldehyde thiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C1), dioxo(5-chlorosalicylaldehyde 2-ethylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C2) and dioxo(5-chlorosalicylaldehyde N-phenylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C3) were prepared. The compounds all crystallize in the triclinic space group P-1 with a = 7.3184(3) ?, b = 7.5035(3) ?, c = 14.9713(6) ?, α = 85.005(2)°, β = 85.616(2)°, γ = 66.987(2)° for C1, a = 8.2339(1) ?, b = 10.1739(1) ?, c = 10.4017(1) ?, α = 78.486(1)°, β = 89.312(1)°, γ = 81.730(1)° for C2, a = 7.0591(1) ?, b = 9.5603(1) ?, c = 14.5762(2) ?, α = 76.280(1)°, β = 81.351(1)°, γ = 81.985(1)° for C3. In general, the overall geometry of these complexes can be regarded as a distorted octahedron with the tridentate thiosemicarbazonato ligands (L²⁻) bonded to the MoO₂ ²⁺ core, with the imine nitrogen, phenoxyl oxygen, sulfur atom and one of the terminal oxygen atoms of the dioxomolybdenum occupying the equatorial position. The sixth coordination site is occupied by the dimethylsulfoxide (DMSO) solvent molecules. The adjacent molecules of C1 are linked by N–H···N intermolecular hydrogen bonding, forming polymeric chains that run parallel to the bc plane. On the other hand, C2 is a discrete molecule while the molecules of C3 associate via weak N–H···O hydrogen bonding interaction to form a polymeric chain that runs along the a-axis.     

Structures of Eight Thio(semi)carbazones Derived from 2-Acetylpyrazine, 2-Acetythiazole and Acetophenone

Abstract  The structures of eight related thio(semi)carbazones are described. These are syn,1E-2-acetylpyrazine-3-thiosemicarbazone (1), syn,1E,4Z-2-acetylpyrazine-4-ethyl-3-thiosemicarbazone, (2) and syn,1Z-2-acetylpyrazine-4,4-dimethyl-3-thiosemicarbazone (3), syn,1E,4Z-2-acetylthiazole-4-phenyl-3-thiosemicarbazone (4), syn,1Z-phenyl-4,4-dimethyl-3-thiosemicarbazone (5), syn,1E,4Z-phenyl-4-methyl-3-thiosemicarbazone (6), syn,1E,4Z-phenyl-4-ethyl-3-thiosemicarbazone (7), syn,1E,4Z-2-acetophenone-5-(N-aminothionyl)-3-thiocarbazone (8). Crystal data: for 1: triclinic, P-1, a = 5.4053(10) ?, b = 7.435(3) ?, c = 11.772(4) ?, α = 81.70(3)°, β = 82.59(2)°, γ = 77.38(2)°, and Z = 2: for 2: triclinic, P-1, a = 7.322(3) ?, b = 7.8239(16) ?, c = 9.783(4) ?, α = 87.73(2)°, β = 79.46(3)°, γ = 80.41(2)°, and Z = 2; for 3: orthorhombic, Pnma, a = 13.5210(15) ?, b = 6.6914(5) ?, c = 11.7214(10) ?, and Z = 4; for 4: triclinic, P-1, a = 5.7058(7) ?, b = 9.8776(15) ?, c = 11.869(2) ?, α = 76.389(12)°, β = 86.364(13)°, γ = 88.322(12)°, and Z = 2; for 5: triclinic, P-1, a = 7.5362(3) ?, b = 8.6331(4) ?, c = 9.8753(4) ?, α = 91.401(4)°, β = 102.532(4)°, γ = 110.540(4)°, and Z = 2; for 6: monoclinic, P2(1)/c, a = 10.7178(4) ?, b = 5.5866(2) ?, c = 18.7647(9) ?, β = 104.392(5)°, and Z = 4; for 7: monoclinic, P2(1)/c, a = 8.9557(3) ?, b = 9.7418(4) ?, c = 13.6864(5) ?, β = 94.044(4)°, and Z = 4; for 8: triclinic, P-1, a = 9.8091(5) ?, b = 10.6173(4) ?, c = 16.4691(7) ?, α = 75.540(4)°, β = 80.305(4)°, γ = 65.192(4)°, and Z = 4. Structures 1, 2, 4, 5, 7, and 8 form intramolecular N4–H···N1 hydrogen-bonds. Structures 3 and 5 exist in the tautomeric form in which N1 is protonated. Graphical Abstract  Structures of thio(semi)carbazones were found to fall into two categories: those with intramolecular N4-H…N1 hydrogen-bonds, and those which show a tautomeric form in which N1 is protonated.      

Synthesis and Structure of bis(β-Diketiminate) Chromium(II) Complexes

Abstract  

The new ligand 2,4-N,N′-bis(napthylamino)-pent-2-ene (L^napth) (1) has been synthesized and crystallizes in space group P2₁2₁2₁ with crystal cell parameters a = 8.196(3) ?, b = 9.119(3) ?, c = 25.746(10) ?, V = 1924.3(12) ?³ and Z = 4. The complexes bis[2,4-pentane-N,N′-bis(napthyl)ketiminato] chromium(II) (2), bis[2,4-pentane-N,N′-bis(isopropylphenyl)ketiminato] chromium(II) (3), and bis[2,4-pentane-N,N′-bis(tertbutylphenyl)ketiminato] chromium(II) (4) were synthesized and structurally characterized. Complex 2, the first complex reported with a bis(napthyl) β-diketiminate ligand, crystallizes in space group P − 1 with crystal cell parameters a = 12.0824(15) ?, b = 12.2462(16) ?, c = 14.8975(19) ?, α = 87.035(2)°, β = 80.615(2)°, γ = 62.756(2)°, V = 1932.9(4) ?³ and Z = 2. Complex 3 crystallizes in space group P2₁/n with crystal cell parameters a = 13.088(3) ?, b = 22.222(5) ?, c = 14.206(3) ?, β = 102.310(4)°, V = 4036.6(17) ?³ and Z = 4. Complex 4 crystallizes in space group P2₁/n with crystal cell parameters a = 20.831(6) ?, b = 11.575(4) ?, c = 21.373(7) ?, β = 107.241(5)°, V = 4922(3) ?³ and Z = 4. The degree of twist between the ligand planes is dependent on the steric bulk of the ligand.     

Characterization of Molecular Complexes of 1,4-Naphthoquinone Derivatives

Abstract  

The structures of sulphur atom tethered quinone containing flexible carboxylic acid (3-methyl-1,4-dioxo-1,4-dihydronaphthalen-2-ylsulfanyl)acetic acid (1) and its molecular complex with 4,4′-bipyridine (3) are determined. The compound 1 crystallizes in P-1 (triclinic, a = 7.5378(6) ?, b = 7.6413(7) ?, c = 10.3101(9) ?; α = 89.779 (7)°, β = 81.042 (5)°, γ = 89.101(7)°) and the molecular complex 3 crystallises in P2(1)/n (monoclinic, a = 9.3383(7) ?, b = 3.970(3) ?, c = 42.130(3) ?, β = 91.056(5)°) space groups, respectively. The R₂²(8) type hydrogen bonding between dicarboxylic acid groups present in the parent compound 1 is lost on interaction with 4, 4′-bipyridine; in the molecular complex 3 R₂²(7) type of O···H–C and O–H···N interactions are present between the pyridine rings and carboxylic acid groups. The molecular complex (4) derived from 3-carboxymethylsulfanyl-1,4-dihydroxynaphthalen-2-yl-sulfanyl) acetic acid (2) with triphenylphosphine oxide in 1:2 ratio, crystallises in C2/c space group have monoclinic, a = 26.0494(13) ?, b = 10.5402(5) ?, c = 17.1023(8) ?, β = 108.719 (5)°). The triphenylphosphine oxide molecules are preferentially held by O–H···O interactions between carboxylic acid and P=O bond.     

Structural Modulation in Lanthanide Tetracyanoplatinates Incorporating Terpyridine: Synthesis and Structures of Four Distinct One-Dimensional Variants

Abstract  

The synthesis of four different lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine have been carried out in acetonitrile/water mixtures by reaction of an appropriate Ln³⁺ salt with 2,2′:6′,2″-terpyridine and potassium tetracyanoplatinate. The use of different Ln³⁺ salts as reactants results in the isolation of {La(tpy)(H₂O)₃}₂[Pt(CN)₄]₃·2CH₃CN·2H₂O (La-1) space group P[`1] P\bar{1} , a = 9.3862(15) ?, b = 12.186(1) ?, c = 13.493(1) ?, α = 88.082(7)°, β = 80.22(1)°, γ = 74.88(1)°, {Pr(tpy)(H<sub>2</sub>O)<sub>3</sub>}<sub>2</sub>[Pt(CN)<sub>4</sub>]<sub>3</sub>·2H<sub>2</sub>O (Pr-2) space group P[`1] P\bar{1} , a = 9.2458(15) ?, b = 10.8068(9) ?, c = 13.6178(14) ?, α = 84.554(8)°, β = 74.905(10)°, γ = 79.490(9)°, Ho(tpy)(H₂O)₂(NO₃)[Pt(CN)₄] · CH₃CN (Ho-3) space group P2₁/c, a = 12.867(1) ?, b = 15.1046(15) ?, c = 13.651(4) ?, β = 105.39(1)°, or Yb(tpy)(H₂O)₂(NO₃)[Pt(CN)₄]·0.5CH₃CN·1.5H₂O (Yb-4) space group Pbcn, a = 13.226(7) ?, b = 15.870(2) ?, c = 24.276(3) ? under quite similar reaction conditions. All four of these compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. None of these compounds are isostructural with one another, but all contain one-dimensional, polymeric structures that contain tris chelation of the Ln³⁺ cations by terpyridine and bridging of the Ln³⁺ ions by tetracyanoplatinate. La-1 and Pr-2 contain both cis- and trans-bridging of Ln³⁺ cations by tetracyanoplatinate resulting in double chains with a ladder-type structure. Ho-3 and Yb-4 are similar in that they contain chelation of Ln³⁺ by both terpyridine and a nitrate anion and both structure types only contain cis-bridging by tetracyanoplatinate. All four structures contain Pt–Pt interactions in the form of dimeric units.     

Synthesis and Crystal Structure of Benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran-18-carbonate Ester

Abstract  Isosteviol derivative: benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran-18-carbonate ester was synthesized by esterification of isosteviol with chloromethyl benzoate and its crystal structure was determined by X-ray diffraction method. The compound crystallizes in the triclinic space group P1 with unit cell parameters: a = 8.784(3) ?, b = 9.079(3) ?, c = 15.950(6) ?, α = 79.343(6)°, β = 79.061(5)°, γ = 89.849(5)°, Z= 2. The conformation of rings A and B is chair, whereas the conformation of ring C is unsymmetrical twist chair. The carbonyl group at the C20 is coplanar with the benzene ring. The fragment of the ester group occupying the pseudoaxial site of C1 position adopts a zigzag conformation. Index Abstract  Isosteviol derivative: benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran -18-carbonate ester was synthesized and its crystal structure was determined by X-ray diffraction method.      

Synthesis and Crystal Structure of Compound 1-Phenyl-2-(1H-1,2,4-triazolo-yl)-3-phenyl-propen-1-one and 1-Diphenyl-3-(1,2,4-triazolo-yl)-1H,4H-1,5-benzothiazepine

Abstract  

The crystal structures of the compounds 1-phenyl-2-(1H-1,2,4-triazolo-yl)-3-phenyl-propen-1-one (2), and 2,4-diphenyl-3-(1,2,4-triazolo-yl)-1H,4H-1,5-benzothiazepine (3) were obtained by single crystal X-ray diffraction. Compound 2 crystallizes in the triclinic system with space group P − 1, a = 8.5553(17) ?, b = 9.6229(19) ?, c = 9.924(2) ?, α = 106.16(3)°, β = 108.03(3)°, γ = 105.14(3)°, V = 690.1(2) ?³, Z = 2. The compound 3 crystallizes in the orthorhombic system with space group Pbca, a = 12.904(3) ?, b = 15.864(3) ?, c = 19.140(4) ?, α = 90°, β = 90°, γ = 90°, V = 3918.3(14) ?³, Z = 8. H-bonds and π–π stacking are the main non-bonding interactions in the molecular structure. Details of the synthesis, structures, and spectroscopic properties of the two compounds are discussed.     

A Facile Synthesis and Crystallographic Analysis of Seven Trityl Phosphorus Compounds and Two Nickel(II) Phosphine Side-Products

Abstract  The syntheses and X-ray analyses of triphenylmethyl (trityl=Tr) phosphorus compounds are reported and the structural similarities, differences and ³¹P chemical shifts compared. A series of seven trityl-substituted phosphorus-containing compounds have been characterized by single crystal X-ray diffraction. Ph₃CPPh₂, 1, a bulky P(III) compound crystallizes in the triclinic space group , a = 7.5624(6) ?, b = 9.5470(8) ?, c = 16.9722(14) ?, α = 83.4720(10)°, β = 80.541(2)°, γ = 68.1580(10)°, the borane complex of 1, 2, Ph₃CPPh₂(BH₃) crystallizes as monoclinic colorless crystals, P2₁/c, a = 10.0972(12) ?, b = 9.6955(12) ?, c = 25.197(3) ?, β = 90.258(2)°. The analogous methyl substituted, 3, Ph₃CPMe₂(BH₃) is monoclinic, C₂/c, a = 15.628(3) ?, b = 12.770(3) ?, c = 18.406(4) ?, β = 103.968(3)°. Compounds 4–7 are trityl substituted P(V) compounds: Ph₃CP(Ph)(O)(OH), 4, crystallizes in the triclinic space group , a = 8.9847(18) ?, b = 9.7443(19) ?, c = 12.786(3) ?, α = 72.045(3)°, β = 72.031(3)°, γ = 78.769(3)°. Esterification of 4 affords TrCP(O)(Ph)OBn 5, space group, P2₁/c, a = 7.9196(5) ?, b = 31.701(2) ?, c = 19.8062(13) ?, β = 99.7750(10)°. A phosphonate diester was also characterized, Ph₃CP(O)(OEt)₂, 6, triclinic, , a = 7.9521(17) ?, b = 9.2205(19) ?, c = 14.471(3) ?, α = 85.906(4)°, β = 83.031(4)°, γ = 68.283(4)°. Treatment of the trityl H-phosphinic acid, Ph₃CPO₂H_2, with elemental selenium yields yellow crystals of 7, [Ph₃CP(O)(OH)Se]_2, P2₁/c, a = 9.0603(4) ?, b = 22.3652(11) ?, c = 16.9134(7) ?, β = 107.035(2)°. In our efforts to isolate a nickel-phosphine complex, two Ni(II) complexes were crystallographically analyzed, [Ni(OP(H)Ph₂)₆]₂BF₄ ⁻ 8 and 9. Complex 8 with an uncoordinated BF₄ ⁻ ion crystallizes as yellow orthorhombic crystals, Pbca, a = 18.8247(12) ?, b = 18.5518(12) ?, c = 21.0976(14) ?, while crystals of 9 are trigonal, , a = b = 13.1545(12) ?, c = 68.461(9) ?. Graphical Abstract  The syntheses and X-ray analyses of triphenylmethyl (trityl=Tr) phosphorus compounds are reported and the structural similarities, differences and ³¹P chemical shifts compared.      

Synthesis and Structural Characterization of (2,4-Diamino-5-(3′,4′,5′-Trimethoxybenzyl)Pyrimidine Copper (II)) Complex

Abstract  The reaction of Cu(OOCCH₃)₂·H₂O with (2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl) pyrimidine (trimethoprim) in ethanolic solution at 80 °C affords the title complex which has been characterized by elemental, IR, and NMR (¹H and ¹³C).The crystal structure has been determined by single crystal X-ray diffraction. Compound 1 (C₃₆H₄₈Cu₂N₈O₁₄) is triclinic, space group P-1 with a = 7.2676(4) ?, b = 11.6721(7) ?, c = 12.8279(8) ?, α = 95.839(1)°, β = 93.456(1)°, γ = 105.541(1)°, Z = 1. Two copper atoms are coordinated directly to each other as well as are held together by four bridging aceto groups. Each copper atom is also bonded opposite the Cu–Cu vector to a trimethoprim molecule through the N(1) atom of the pyrimidine ring. Trimethoprim acts as a monodentate ligand through the pyrimidine nitrogen N(1) atom. The complex was screened for the activity against several bacteria, showing more activity against bacteria as compared to trimethoprim. Graphical Abstract  To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria was analyzed.      

Synthesis and Crystal Structures of N′-3,5-Dibromo-2-Hydroxybenzylidene)-2-Hydroxy-3-Methylbenzohydrazide and its Oxovanadium(V) Complex [N′-(3,5-Dibromo-2-Oxidobenzylidene-κO)-2-Hydroxy-3-Methylbenzohydrazidato-κ2N′,O](Methanol-κO)(Methanolato-κO)Oxidovanadium(V)

Abstract  

A new hydrazine ligand N′-3,5-dibromo-2-hydroxybenzylidene)-2-hydroxy-3-methylbenzohydrazide (1) and its oxovanadium(V) complex [N′-(3,5-dibromo-2-oxidobenzylidene-κO)-2-hydroxy-3-methylbenzohydrazidato-κ ² N′,O](methanol-κO)(methanolato-κO)oxidovanadium(V) (2), were prepared and were structurally characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P−1, with unit cell dimensions a = 7.813(2) ?, b = 8.748(2), c = 26.071(6) ?, α = 85.763(2)°, β = 81.521(2)°, γ = 89.358(3)°, V = 1757.6(7) ?³, Z = 4, R ₁ = 0.0587, and wR ₂ = 0.1054. Compound 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a = 7.777(3) ?, b = 11.594(3), c = 12.363(3) ?, α = 107.965(3)°, β = 103.190(2)°, γ = 96.656(2)°, V = 1011.3(5) ?³, Z = 2, R ₁ = 0.0634, and wR ₂ = 0.1480. The hydrazine ligand coordinates to the V atom through the phenolic O, imino N, and ethanolic O atoms. The V atom in the complex is in an octahedral coordination, with the three donor atoms of the hydrazine ligand and one methanolato O atom defining the equatorial plane, and with one methanol O and one oxo O atoms occupying the axial positions. The displacement of the V atom from the equatorial plane towards the axial oxo O atom is 0.305(2) ?.     

Solid-State Intermolecular Contacts Involving the Nitrile Group in p-Cyano-N-(p-cyanobenzylidene)aniline and 4,4′-(azinodimethylidyne)bis-benzonitrile

Abstract  

As part of an investigation of the solid-state intermolecular contacts in which the nitrile group participates, the crystal structures of p-cyano-N-(p-cyanobenzylideneaniline), C₁₅H₉N₃ (CN/CN) and 4,4′-(azinodimethylidyne)bis-benzonitrile, C₁₆H₁₀N₄ (CN//CN) have been determined at −100 °C. Cell parameters for CN/CN: a = 4.7270(9) ?, b = 10.443(2) ?, c = 11.943(2) ?; α = 90°, β = 98.70(3)°, γ = 90°; monoclinic, space group P2₁/c. Cell parameters for CN//CN: a = 3.8008(8) ?, b = 7.9627(16) ?, c = 11.181(2) ?; α = 70.23(3)°, β = 84.66(3)°, γ = 81.93(3)°; triclinic, space group P[`1] P\overline{1} . Both molecules occupy crystallographic inversion centers, which requires that (CN/CN) be disordered. Both molecules assume nearly planar conformations in the solid state. Neither (CN/CN) nor (CN//CN) is isostructural with its halogen-nitrile substituted analogues, although (CN/CN) is found to be isostructural with the corresponding stilbene. Both (CN/CN) and (CN//CN) engage in centrosymmetric H-bonding interactions that define an R ₂²(10) motif. This motif is also observed in many related structures, although noteworthy exceptions can be found.     

Synthesis and Crystal Structures of α-Phenyl- and α-Trifluoromethyl-α-(2-pyridyl-N-oxide)ethanols and α-Phenyl-α-(2-pyridyl-N-oxide)ethylene

Abstract  

The X-ray structures of two α-substituted α-(2-pyridyl-N-oxide)ethanols, the α-phenyl- (3a) and α-trifluoromethyl- (3b) derivatives, were determined. On dehydration of 3a, compound 4a was obtained. This study brought a clear proof that the α-(2-pyridyl-N-oxide)ethanols are formed following oxidation with peroxides of their corresponding pyridines. A different molecular packing was observed for the α-trifluoromethyl derivative due to an additional hydrogen bonding. Compound 3a crystallized in the monoclinic space group P 2₁/n with unit cell parameters a = 5.7416(1) ?, b = 14.3841(4) ?, c = 13.2821(3) ?, β = 94.918(2)°, V = 1092.90(4) ?³, Z = 4, D = 1.308 Mg/m³. Compound 3b crystallized in the triclinic space group P −1 with unit cell parameters a = 6.1209(2) ?, b = 8.1938(4) ?, c = 9.4675(4) ?, α = 73.363(3)°, β = 73.166(3)°, γ = 71.659(3)°, V = 421.32(3) ?³, Z = 2, D = 1.633 Mg/m³. Compound 4a crystallized in the monoclinic space group P 2₁/n with unit cell parameters a = 9.3579(3) ?, b = 12.7340(3) ?, c = 9.8579(3) ?, β = 117.3249(15)°, V = 1043.63(5) ?³, Z = 4, D = 1.255 Mg/m³.     

Variable Ag—O bonding patterns in silver cyclic amide tri-aryl-phosphine complexes

The solid-state structures of five new tri-arylphosphine silver cyclic amide complexes having a systematic variation in the ring structures have been resolved. Normal Ag—N bonding and variable, weaker Ag—O bonding interactions, which can be attributed to the ring modifications, form the basis of the bonding patterns. Reported here are the solid-state structures of silver complexes of tri-arylphosphine derivatives of silver 1(2H)-phthalazinone, silver phthalimide, silver 1,2,3-benzotriazin-4(3H)-one, silver 2H-1,3-benzoxazine-2,4(3H)-dione and silver 2,3-dihydro-1,4-phthalazine- dione. The unit cell parameters are: P-1, a = 11.179(2) ?, b = 15.508(3) ?, c = 22.636(5) ?, α = 104.30(3)°, β = 95.39(3)°, γ = 94.62(3)°; C2/c, a = 17.3600(8) ?, b = 15.4930(8) ?, c = 15.0760(7) ?, β = 113.911(2)°; P-1, a = 11.0656(2) ?, b = 11.9447(2) ?, c = 17.4764(3) ?, α = 79.5254(9)°, β = 80.2877(9)°, γ = 68.9136(7)°; P-1, a = 10.5743(4) ?, b = 11.8439(4) ?, c = 19.0110(8) ?, α = 102.4280(13)°, β = 104.0330(12)°, γ = 100.2520(18)°, P-1, a = 13.6908(3) ?, b = 16.2230(4) ?, c = 18.3678(7) ?, α = 86.8920(10)°, β = 69.5290(10)°, γ = 70.7840(10)°, respectively. Four of the complexes include ligand chelation by Ag—O bonding to the adjacent carbonyl in addition to the main Ag—N connection.     

Structures of Bis(1-ethylbenzimidazol-2-yl)alkyl Copper(II) Dichlorides: An Unusual Cocrystallization

Abstract  Two structures containing pseudo-tetrahedral Cu(II)N₂Cl₂ coordination complexes are reported. The first molecular structure (A) of the compound, 1,1′bis(1-ethylbenzimidazol-2-yl)propane copper(II) dichloride (triEtBBIM)Cu(II)Cl₂, 1, is reported. The complex crystallized in the triclinic space group P-1 with a = 8.616(3) ?, b = 9.302(3) ?, c = 14.314(4) ?, α = 85.613(6)°, β = 85.170(6)°, γ = 66.117(6)° and V = 1044.1(5) ?³ with Z = 2. The second structure (B) contains 1 and (3,3′bis(1-ethylbenzimidazol-2-yl)pentane) copper(II) dichloride (tetEtBBIM)Cu(II)Cl₂, 2, both of which, cocrystallize in an equal molar ratio with a nitromethane solvate molecule. The complex crystallized in the monoclinic space group P2₁/c with a = 18.876(4) ?, b = 14.975(3) ?, c = 18.344(4) ?, β = 116.75(3)°, and V = 4630.3(16) ?³ with Z = 4. The cocrystallization of such discrete complexes has been coined a chemical Janus. Graphical Abstract  The title complexes contain pseudo-tetrahedral Cu(II)N₂Cl₂ coordination. One of the structures is the result of an unusual cocrystallization, in which two different discrete Cu(II) molecules cocrystallize in an equimolar ratio with a nitromethane solvate molecule.      

Synthesis,Characterization and Fluorescent Property of Two Mixed Ligand Coordination Polymers Constructed from 4-Cyclohexene-1,2-dicarboxylate and Nitrogen-Containing Ligands

Abstract  

Two new coordination polymers [Cd(1,2′-cy)(btx)_0.5H₂O]_n 1 and {[Ni(1,2-cy)(2,2′-bipy)(H₂O)₂]·3H₂O}_n 2 (1,2′-cy=4-cyclohexene-1,2-dicarboxylate, btx=1,4-bis(triazol-1-ylmethyl)benzene, 2,2′-bipy=2,2′-bipyridine) had been synthesized. Their structures were characterized by elemental analysis, IR, TG and X-ray single-crystal diffraction analysis. Crystal data for complex 1: Triclinic, space group P-1, a = 6.4303(13) ?, b = 10.399(2) ?, c = 11.713(2), α = 83.04(3)°, β = 81.87(3)°, γ = 83.84(3)°, and Z = 2. For complex 2: Orthorhombic, space group Pbcn, a = 15.613(3) ?, b = 13.970(3) ?, c = 21.290(4) ?, and Z = 4. Complex 1 exhibits an interesting two-dimensional wavelike covalent layer structure. When Ni salt was replaced by Cd salt, and reacts with 1,2′-cy and 2,2′-bipy, one-dimensional chain-like complex 2 was obtained. Furthermore, the fluorescent property of complex 1 was reported.