Synthesis and Crystal Structure Analysis of Methyl 2-Hydroxyimino-3-phenyl-propionate

Abstract  

As precursors of α-amino acids, methyl 2-hydroxyimino-3-phenyl-propionate (F.W. 193.20) was synthesized, characterized by ¹H NMR, IR, element analysis and confirmed by X-ray crystal structure analysis. This compound crystallizes in monoclinic class under the space group P2₁/c with cell parameters, a = 8.6435(17) Å, b = 5.4957(11) Å, c = 21.146(4) Å; β = 97.12(3)°, and Z = 4. The structure exhibits inter-molecular hydrogen bonds of the type O–H···N, O–H···O, C–H···O.     

Hydrogen Bonded 3D Supramolecular Architectures of Two Organic Salts Assembled from 2-Aminoheterocyclic Compounds and Phosphoric Acid

Abstract  

Two phosphate salts (2-aminopyrimidine): (phosphoric acid): H₂O [HL1⁺ (H₂PO₄) ⁻ ]·H₂O (1), and (4-phenylthiazol-2-amine): (phosphoric acid) [HL2⁺·(H₂PO₄)⁻] (2) based on 2-aminoheterocyclic compounds, 2-aminopyrimidine (L1), and 4-phenylthiazol-2-amine (L2) were prepared and structurally characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic, space group P-1, with a = 6.2201(7) Å, b = 8.6139(9) Å, c = 9.4800(10) Å, α = 109.685(2)°, β = 106.3340(10)°, γ = 95.4450(10)°, V = 448.72(8) Å³, Z = 2. For 1, the cations were linked to each other via intermolecular C–H···N hydrogen bonds to form a 1-D chain structure running along the a-axis direction. The anions and the water molecules were connected alternatively along the a-axis direction through O–H···O hydrogen bonds to form a 1-D chain also. The cationic chains and the anionic chains were alternatively connected along the c-axis direction through N–H···O and C–H···O hydrogen bonds to form a 2D corrugated sheet. Adjacent sheets were combined together through π–π interaction to form double sheet. These double sheets were further joined together by O–H···O and N–H···O hydrogen bonds to produce a 3D network structure. Compound 2 crystallizes in the Orthorhombic, space group Pbca, with a = 10.1929(10) Å, b = 8.4406(9) Å, c = 27.589(2) Å, α = 90°, β = 90°, γ = 90°, V = 2373.6(4) Å³, Z = 8. In 2, the phosphates formed 1D chain along the b-axis through two P–O–H···O = P hydrogen bonds. The cations formed 1D zigzag chain along the b-axis direction under the CH–π interaction. The anionic chains were intercalated between two adjacent cationic chains through N–H···O, O–H···O, C–H···O, and O–S contacts. Such stacking repeated along the c-axis direction to form a 3D network structure.     

Synthesis, Spectroscopic Characterization and Crystal Structure of a New Acetyl phosphorylamidate P(O)[NHC(O)C6H4(4-NO2)][N(CH(CH3)2)(CH2C6H5)]2

Abstract  

A new acetyl phosphorylamidate P(O)[NHC(O)C₆H₄(4-NO₂)][N(CH(CH₃)₂)(CH₂C₆H₅)]₂ has been synthesized and characterized by elemental analysis, ¹H, ¹³C and ³¹P NMR, IR and single crystal X-ray diffraction. Single crystal X-ray analysis shows that it belongs to triclinic system, space group P[`1] P\bar{1} , with a = 10.5868(16) Å, b = 11.8058(18) Å, c = 12.4364(19) Å, α = 65.410(3)°, β = 67.492(4)°, γ = 85.879(3)°, V = 1,298.6(3) Å³, and Z = 2. The intermolecular PO···HN hydrogen bond makes H-bonded dimer of molecule with Ci symmetry. In the crystal network, the dimers are aggregated in the chain arrays through π-stacking between p-NO₂–C₆H₄–C(O)–NH– moieties. Moreover, weak C–H···O and C–H···π interactions exist in the crystal network.     

Synthesis,Crystal Structure and Optical Properties of a Three-Dimensional Supramolecule Assembled by a Dinuclear Neodymium Cluster

Abstract  

The reaction of isonicotinic acid (IN), sodium hydroxide, 1,10-phenanthroline (phen) and neodymium nitrate leads to the formation of a novel complex [Nd(phen)(IN)₂(NO₃)(H₂O)₂]₂ 1, which has been characterized by single crystal X-ray diffraction analysis: monoclinic, space group C2/c, with a = 24.93(2) Å, b = 9.452(3) Å, c = 21.406(5) Å, β = 97.87(2)°, and Z = 4. Complex 1 consists of a centrosymmetric dinclear molecule, and neodymium atoms are bridged by two carboxyl groups of two IN ligands. The dinuclear clusters of 1 are connected each other into a three-dimensional (3D) supramolecular framework, which is stabilized by O–H···O, O–H···N hydrogen bonds as well as π–π stacking interactions. Its electronic absorption and luminescence properties have also been investigated.     

Synthesis,Crystal Structure and Hydrogen-Bonding Patterns in (RS)-1-Carbamoyl Pyrrolidine-2-Carboxylic Acid

Abstract  

The title compound, N-carbamoyl-dl-proline, C₆H₁₀N₂O₃, crystallizes in the triclinic P-1 space group with unit cell parameters a = 7.610 (4) Å, b = 9.259 (5) Å, c = 11.749 (7) Å, α = 110.294 (11)°, β = 101.304 (13)°, γ = 91.391 (16)°, with two crystallographically independent molecules in the asymmetric unit. The ureido and carboxyl groups are equatorial and axial to the pyrrolidine rings, respectively. The pyrrolidine rings adopt envelope and twisted conformations in the residue A and B, respectively. The molecules are joined by N–H···O and O–H···O hydrogen bonds into cyclic structures with graph set R ₂²(8), forming infinite chains parallel to the cb plane with graph set C ₂²(14), that are further connected via N–H···O hydrogen bonds into a three-dimensional network.     

Crystal Structure of Ethyl (2Z, 5R)-2-benzylidene-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-[1,3] Thiazolo [3,2-a] Pyrimidine-6-carboxylate

Abstract  

The title compound, C₂₃H₂₀N₂O₃S, (I), crystallizes in the orthorhombic space group, Pna 2 ₁ , with cell parameters a = 18.7975(6), b = 12.5173(4), c = 8.4804(3) Å, Z = 4. The molecular structure consists of a central pyrimidine ring which is significantly puckered to assume a screw-boat conformation fused to a thiazole ring with benzyl, carboxylate, methyl, phenyl and oxy groups bonded around this fused-ring moiety. The dihedral angle between the mean planes of the thiazole, benzyl and phenyl groups and the mean plane of the pyrimidine ring is 6.1(4)°, 83.8(7)° and 6.8(4)°, respectively. The dihedral angle between the mean planes of the benzyl and phenyl rings is 88.3(5)° while between the mean planes of the phenyl and thiazole groups measures 12.6(6)°. In the absence of expected hydrogen bonding interactions, the crystal packing is influenced by a collective action of strong intramolecular C–H···S hydrogen bond interactions, close C–H···O intramolecular contacts and O–Cg π-ring interactions. A DFT molecular orbital calculation gives support to these observations.     

Anchor Effect on Pedal Motion Observed in Crystal Phase of an Azobenzene Derivative

Abstract  

Some molecules having a molecular skeleton similar to that of stilbenes and azobenzenes show orientational disorder in the crystals due to pedal motion. Heretofore, the orientational disorder through pedal motion has been observed for the compounds containing only two aromatic rings in the absence of bulky substituent groups. Here we report that the pedal motion can be detected even in the presence of a bulky substituent group to which orientational disorder becomes invisible as a result of anchor effect arising from phenoxyphtalonitrile group. X-ray crystallographic analysis of the compound, C₂₃H₁₈N₄O, reveals the existence of partially overlapped two pedal conformers. The compound crystallizes in the monoclinic space group P2₁/c with a = 12.9429(11) Å, b = 8.5075(5) Å, c = 21.063(2) Å and β = 123.155(6)°. Major pedal conformer is stabilized by weak C–H···O type hydrogen bond and C–H···π type edge-to-face interactions in solid state. Quantum chemical calculations at B3LYP/6-311G+(d,p) level suggest that the stabilization of the compound decreases with increasing deviation from the planar geometry of trans-azobenzene fragment.     

Crystal Structure of 3-(4-Methoxy-benzylidene)-isothiochroman-4-one

Abstract  

The title compound, 3-(4-methoxy-benzylidene)-isothiochroman-4-one (C₁₇H₁₄O₂S) was prepared from the reaction of isothiochroman-4-one with benzaldehyde in the presence of small amount of HCl. The structure of the synthesised compound was determined by IR, ¹H NMR and X-ray crystallography. The structure was solved in monoclinic, space group P2₁/n with a = 3.9773 (7) Å, b = 10.918 (2) Å, c = 30.609 (6) Å, β = 90.615 (3)°, V = 1329.1 (4) Å³, Z = 4 and with R _int = 0.047. The bicyclic ring of isothiochroman-4-one moiety does not adopt a planar geometry. The molecular conformation is stable via C10–H···O1 and C16–H···S1 intramolecular hydrogen-bonding interactions. These contacts involve molecules in an extended two-dimensional sheet to the bc plane.     

5-Pyridine 4-yl-3H-(1,3,4) Oxadiazole-2 Thione Hydrochloride Monohydrate, (I), and 4 [5-Ethylsulfanyl)-(1,3,4) Thiadiazole-2-yl]-Pyridinium Perchlorate, (II)

Abstract  

The title compounds C₇H₈ClN₃O₂S, (I), and C₉H₁₀ClN₃O₄S_2, (II), both crystallize in monoclinic space group P2₁ /c with unit cell parameters (I) a = 7.9402(7), b = 10.6312(9), c = 11.7626(10), ?, β = 99.271(5)°, Z = 4 and (II) a = 5.1439(2), b = 9.0636(4), c = 27.1814 (7), ?, β = 95.116(2)°, Z = 4. In (I) the molecule consists of a 5-pyridine-4-yl group bonded to the carbon atom at the 5 position of (1, 3, 4) oxadiazole-2 thione hydrochloride monohydrate. The angle between the mean planes of the oxadiazole and pyridine rings is 9.6(6)°. Crystal packing in (I) is stabilized by strong N–H···O hydrogen bonds in concert with a solvent water molecule and weak O–H···Cl, O–H···S, N–H···Cl intermolecular interactions. The crystal structure of compound (II) consists of 4 [5-ethylsulfanyl)-(1, 3, 4) thiadiazole-2-yl]-pyridinium perchlorate, (C₉H₁₀N₃S₂)⁺(ClO₄)⁻, cation–anion pairs, containing strong intermolecular N–H···O hydrogen bonds and weak C–H···O and N–H···O intermolecular interactions operating between the ionic species that form a cooperative hydrogen-bonded, infinite chain O–H···O–H···O–H network which generates a sheet motif structure in the unit cell. It is also supported by weak intermolecular Cg···Cg π–π and Cl–O···Cg π-ring interactions which gives additional support to molecular packing stability in the unit cell. Geometry optimized MOPAC AM1 computational calculations on each compound provides support to the structural features in their respective crystal structures.     

Hydrogen Bonding in the Water Stabilized Structure of the Modified Unsymmetrically Substituted Viologen Chromophore, <Emphasis Type="Italic">N</Emphasis>-ethyl-<Emphasis Type="Italic">N</Emphasis>′-(2-phosphonoethyl)-4,4′-bipyridylium Dichloride

Abstract  

The crystal structure of the modified unsymmetrically N,N′-substituted viologen chromophore, N-ethyl-N′-(2-phosphonoethyl)-4,4′-bipyridinium dichloride 0.75 hydrate (1) has been determined. Crystals are triclinic, space group P−1 with Z = 2 in a cell with a = 7.2550(1), b = 13.2038(5), c = 18.5752(7) Å, α = 86.495(3), β = 83.527(2), γ = 88.921(2)°. The two independent but pseudo-symmetrically related cations in the asymmetric unit form one-dimensional hydrogen-bonded chains through short homomeric phosphonic acid O–H···O links [2.455(4), 2.464(4) Å] while two of the chloride anions are similarly strongly linked to phosphonic acid groups [O–H···Cl, 2.889(4), 2.896(4) Å]. The other two chloride anions together with the two water molecules of solvation (one with partial occupancy) form unusual cyclic hydrogen-bonded bis(Cl···water) dianion units which lie between the layers of bipyridylium rings of the cation chain structures with which they are weakly associated.     

N,N′-Dihydrogenpiperazonium dichloridobis(dimethylglyoximato-k2N,N′)cobaltate(III) Dihydrate

Abstract  

The title complex: C₄H₁₂N₂[Co(C₄H₇N₂O₂)₂Cl₂]₂·2H₂O, viz., PpH₂[Co(dmgH)₂Cl₂]₂·2H₂O, where, dmgH⁻ = dimethylglyoximate and Pp = piperazine was synthesized and analyzed by single crystal XRD studies. The complex was grown as brown crystals by the slow evaporation method in ethanol. The complex crystallizes as triclinic with the space group p[`1] p\overline{1} and unit cell parameters a = 8.4521 (10) Å, b = 10.0999 (11) Å, c = 10.8952(13) Å; α = 94.066(6)°, β = 106.047(6)° and γ = 100.901(6)°. There are two complex molecules present in the unit cell. The short intra molecular O–H···O hydrogen bonds link the glyoximate moieties in the crystal.     

Low Temperature Crystal Structure of 5-Hydroxy-1,7-Bis-(4-Hydroxy-3-Methoxy-Phenyl)-Hepta-1,6-Dien-3-one

Abstract  

The title compound 5-Hydroxy-1,7-bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-dien-3-one crystallizes in orthorhombic space group Pca2₁ with two molecules in the asymmetric unit. The unit cell parameters are: a = 35.5368(8), b = 7.7799(2), c = 12.6796(3) ?, D _calc = 1.396 Mgm⁻³, V = 3505.6(2) ?³ and Z = 8. The two aromatic rings in both the molecules are found almost coplanar, their dihedral angles are 18.8° and 13.8°, respectively. The molecular packing is stabilized by strong O–H···O and C–H···O types of hydrogen bonding interactions. The keto and enol groups form an strong O–H···O intra-molecular interaction in both molecules of asymmetric unit. The molecular alignment in the crystal forming a staircase type of stacking through cross link intermolecular interactions.     

Synthesis,Crystal Structure and Characterizations of New 3,4,7,8-Tetrachloro-1,10-Phenanthroline Zn(II) Complex

Abstract  

A novel 3,4,7,8-tetrachloro-1,10-phenanthroline (Cl₄phen) Zn(II) complex has been synthesized. The complex, [Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH₃CH₂OH (1), has been identified and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence studies. Single crystal X-ray diffraction analysis reveals that complex (1) belongs to the monoclinic system, space group P2(1)/c, a = 10.061(2) Å, b = 18.924(4) Å, c = 18.189(4) Å, β = 100.94(3)°, and Z = 4. Complex (1) consists of cationic species [Zn(Cl₄phen)₂(H₂O)₂]²⁺, NO₃ ⁻ and CH₃CH₂OH. The zinc atom displays a distorted cis-N₄O₂ octahedral geometry. Via extended Zn–O–H···O–N–O···H–O–Zn bridge, every mononuclear unit is linked with other ones to form one-dimensional (1D) infinite chain of hydrogen bond system. Three-dimensional (3D) polymeric network arrangement was built via weak C–H···O and π-stacking interactions between Cl₄phen moieties. A solvent-dependency effect of complex (1) was observed in spectroscopic properties.     

Spectral and X-ray Diffraction Studies of <Emphasis Type="Italic">N</Emphasis>-(2-Nitrophenyl)-5-Phenyl-1,3,4-Oxadiazole-2-Amine

Abstract  

Thiosemicarbazides and their derivatives are well known for their use in biological activity and many applications in pharmaceutical and industrial fields. The cyclization of 1-benzoyl-4-(2-nitrophenyl)-3-thiosemicarbazide (BNPTSC) in dimethylformamide (DMF) medium furnished N-(2-nitrophenyl)-5-phenyl-1,3,4-oxadiazole-2-amine (NPPOA). The chemical structure of the above substituted 1,3,4-oxadiazole has been assigned by IR, mass and X-ray diffraction studies. The XRD studies reveal the presence of four types of hydrogen bonds (N–H···O, N–H···N, C–H···O, C–H···N) in the crystal packing. The crystal system was found to be orthorhombic with a space group Pca2(1) and the unit cell dimensions are: a = 26.873(3) ?, b = 6.0827(7) ?, c = 7.8502(10) ?, α = 90°, β = 90°, γ = 90° and Z = 4.     

Crystal and Molecular Structure Studies of 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo-[3.2.1]octane-3,4′-imidazolodine]-2′,5′-dione

Abstract  

The title compound, C₂₃H₂₃FN₃O₂ has been synthesized and the structure was investigated by X-ray diffraction studies. The compound crystallizes in the triclinic crystal class in the space group P[`1]P\overline{1} with cell parameters a = 9.345(2) ?, b = 10.940(3) ?, c = 11.986(4) ?, α = 72.349(6)°, β = 68.106(18)°, γ = 66.867(5)°, Z = 2 and V = 1027.8(5) ?³. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O, C–H···O and C–H···N. One of the oxygen atoms attached to the hydantoin ring simultaneously accepts two hydrogen bonds to form a three centered hydrogen bonding pattern.     

Crystal Structure of 3-Hydroxy-3′,4′-Methylenedioxy Flavone-6-Carboxylic Acid Dimethylformamide Solvate

Abstract  

The optically pure 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was obtained through the chalcone route. The structure of 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was first elucidated by single crystal X-ray analysis: triclinic, space group, triclinic (P-1) with a = 8.1379(13) ?, b = 8.9831(14) ?, c = 13.198(2) ?, α = 88.413(2)°, β = 74.908(2)°, γ = 72.987(2)°. V = 889.5(2) ?³, Z = 2. The structure was solved by direct methods and refined to a final R = 0.0413 for 1630 reflections with I > 2σ(I). The crystal structure is stabilized by O–H···O and C–H···O hydrogen bondings and π–π stacking interactions.     

Crystal Structure?4-(2,4-Dihydroxybenzylideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one

Abstract  

The title compound (I), 4-(2,4-dihydroxybenzlideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one was characterized by single crystal X-ray diffraction. This crystal is monoclinic, space group P2₁/c with a = 10.1447(7) ?, b = 7.0972(3) ?, c = 14.6726(10) ?, β = 98107(5)°, V = 1045.85(11) ?³, Z = 4, D _c = 1.487 g/cm³, F ₀₀ = 488, R = 0.039 and wR = 0.1025, S = 1.003, T = 293 (2) K. The title molecule is planar: the angle between the triazole ring and benzene ring is 179.1(1)°. The crystal structure contains two intramolecular (O–H···N and C–H···O) and three intermolecular interaction (O–H···N, N–H···O, and C–H···O). In addition, there is also π–π interactions.     

Hydrogen Bonding Patterns in Trimethoprimium Cinnamate 1.52 Hydrate

Abstract  

In the title compound, [C₁₄H₁₉N₄O₃ ⁺, C₉H₅ O₂ ⁻, H₂O, O0.52] the asymmetric unit contains a protonated trimethoprim cation and a cinnamate anion and two water molecules. The crystal structure was determined by single crystal X-ray diffraction. This compound crystallized in the triclinic system; space group P−1 with the unit cell parameters a = 10.010(2) ?, b = 10.339(3) ?, c = 13.486(8) ?, α = 105.32(3)°, β = 109.88(3)°, γ = 100.89(3)°, V = 1204.6(10) ?³, Z = 2. The cinnamate group is disordered. The trimethoprim (TMP) molecule is protonated at one of the pyrimidine nitrogen atoms. The carboxylate group of the cinnamate anion interacts with the protonated pyrimidine atom N1 and the 2-amino group via a pair of N–H···O hydrogen bonds, generating the R₂²(8) ring motif. The inversion related TMP cations are paired via N–H···N hydrogen bonds. In addition to the base pairing, the O1W atom bridges the 2-amino and 4-amino groups on either side of the paired bases, resulting in a self complementary DADA array. Two inversion related TMP cations and water molecules (O1W) are linked via N–H···O and O–H···O hydrogen bonds, forming a 22 membered ring with graph-set R₄⁴(22).     

Synthesis,Spectroscopic Studies and X-ray Analysis of (<Emphasis Type="Italic">E</Emphasis>)-2-(2-Fluorophenyl)-3-(6-Nitrobenzo[d][1,3]dioxol-5-yl) Acrylic Acid

Abstract  

In the solid-state structure of the title compound, C₁₆H₁₀FNO₆, the configuration about the C=C double bond is E. The compound crystallized in the triclinic system, having space group P-1 with unit cell dimensions a = 5.829(10) ?, b = 8.801(16) ?, c = 13.543(3) ?, α = 87.753(15)°, β = 81.945(15)°, γ = 86.342(14)°. The structure of the molecule is V-shaped and in the crystal the molecules are linked to form inversion dimers connected by pairs of C–H···O hydrogen bonds.     

Synthesis,Characterization and Crystal Structure of (<Emphasis Type="Italic">S</Emphasis>)-2-(2-Hydroxynaphthalen-6-yl)-<Emphasis Type="Italic">N</Emphasis>-((pyridin-4-yl)methyl) Propanamide

Abstract  

The synthesis, characterization and crystal structure of the title compound, (S)-2-(2-hydroxynaphthalen-6-yl)-N-((pyridin-4-yl)methyl) propanamide, is described. The salt is enantiomerically pure and crystallize in the orthorhombic P2₁2₁2₁ chiral space group with a = 7.9174(13) ?, b = 11.1583(18) ?, c = 11.2600(18) ?. Each molecule is linked to four neighboring molecules through the O–H···O and N–H···N hydrogen bonds into a supramolecular helical chain. The O–H···O and N–H···N hydrogen bonds lead to 24-membered open rings. Chains are further connected into layers via extensive interchain H···O and H···C short contacts.