Conformational and structural study of N-nicotinyl N′, N″-bis(diisobutyl amine)phosphoric triamide

Single crystals of C5H4NC(O)NHP(O)[N(i-C4H9)2]2 were prepared and investigated by X-ray crystallography. Interestingly, four symmetrically independent conformers were detected in the structure of this compound by X-ray crystallography. The greatest difference in these conformers was different torsion angles. In all conformers, the phosphoryl and carbonyl groups showed anti-configurations, and the two terminal CH3 groups of each alkyl chain in amine parts have different spatial orientations due to their connection to a prochiral carbon atom. The diastereotopic protons of every CH2 moiety in amine groups also have different spatial orientations. Every conformer forms a centrosymmetric dimer with its own symmetrically generated analog via a hydrogen bond. The first conformer connects to others (A, B, and C) via electrostatic interactions and forms a tetramer. All hydrogen bonds and electrostatic interactions result in the formation of a three-dimensional polymeric network in the crystalline lattice of compound. To find the most stable conformer, density functional theory (DFT) calculations were performed. The computationally optimized geometric parameters are in good agreement with the experimental results. According to DFT calculations, B is the most stable conformer with energy of ?987714.07 kcal/mol. In all conformers the electron density of HOMO is localized on P=O and C=O oxygen atoms and some parts of amine groups, while LUMO is localized on the nicotinamide part of the molecule.     

Cu(II) mediated selective transport of α-amino acids across a bulk liquid membrane using a chiral lipophilic ligand as a carrier

The chiral ligand (R)-1 acts as a carrier for the Cu(II) mediated membrane transport of α-amino acids coupled with the counter-transport of protons.     

Diorganotin(IV) complexes of N-mono-, di- and tri-chloroacetyl,N′,N″-bis(isopropyl) phosphoric triamide

Three new carbacylamidophosphates with formula CH_nCl_3?nC(O)NHP(O)(NHCH(CH₃)₂)₂ (n = 2 (1); n = 1 (2); n = 0 (3)) and their organotin compounds with formula (1)SnCl₂Me₂(μ-1)SnCl₂Me₂ (4), SnCl₂Me₂(2)₂·C₆H₅CH₃ (5) and [SnCl₂Me₂(3)]_n (6) were synthesized and characterized by elemental, IR and NMR spectra analyses. The spectroscopic properties of complexes were compared with those corresponding ligands. The crystal structures of complexes were determined by X-ray crystallography, which reveals that complex 4 is binuclear structure with two non-equivalent Sn atoms. One adopts a distorted trans(C,C) cis(O_P,O_P) cis(Cl,Cl) octahedral configuration, while the other adopts a distorted trigonal bipyramidal geometry composed of two methyl groups, two chlorine atoms and carbonyl group. Molecule 5 is centrosymmetric with two O_P, disordered chlorine and methyl groups in trans positions. Toluene molecules are located in the interlayer spaces of 5. In compound 6, bonding via both PO and CO functionalities forms 1D infinite chain structures along b axis. The Sn–O_P bond length in 6 is significantly longer than the same distance in 4 and 5, while the OP and Sn–Cl bonds are shorter. The bond lengths in these complexes were compared with those of N-benzoyl carbacylamidophosphates.     

Diorganotin(IV) complexes of N-mono-, di- and tri-chloroacetyl,N′,N″-bis(isopropyl) phosphoric triamide

Three new carbacylamidophosphates with formula CH_nCl_3−nC(O)NHP(O)(NHCH(CH₃)₂)₂ (n = 2 (1); n = 1 (2); n = 0 (3)) and their organotin compounds with formula (1)SnCl₂Me₂(μ-1)SnCl₂Me₂ (4), SnCl₂Me₂(2)₂·C₆H₅CH₃ (5) and [SnCl₂Me₂(3)]_n (6) were synthesized and characterized by elemental, IR and NMR spectra analyses. The spectroscopic properties of complexes were compared with those corresponding ligands. The crystal structures of complexes were determined by X-ray crystallography, which reveals that complex 4 is binuclear structure with two non-equivalent Sn atoms. One adopts a distorted trans(C,C) cis(O_P,O_P) cis(Cl,Cl) octahedral configuration, while the other adopts a distorted trigonal bipyramidal geometry composed of two methyl groups, two chlorine atoms and carbonyl group. Molecule 5 is centrosymmetric with two O_P, disordered chlorine and methyl groups in trans positions. Toluene molecules are located in the interlayer spaces of 5. In compound 6, bonding via both PO and CO functionalities forms 1D infinite chain structures along b axis. The Sn–O_P bond length in 6 is significantly longer than the same distance in 4 and 5, while the OP and Sn–Cl bonds are shorter. The bond lengths in these complexes were compared with those of N-benzoyl carbacylamidophosphates.     

Synthesis and structure of 1,1′-bis(pentafluorophenyl)tetrahydrodigermane

Dehydrogenation of pentafluorophenylgermane in the presence of catalytic amounts of a Wilkinson complex, certain Rh^I ortho-benzosemiquinolate complexes, or (Ph₃P)₄Pt leads to tetrahydrodigermane, C₆F₅H₂GeGeH₂C₆F₅. X-ray analysis has confirmed thetrans-arrangement of the C₆F₅-cycles at the Ge atoms. The Ge-Ge bond length is 2.394(1) Å. The doublet pattern of the band due to the Ge-H bonds (v 2090 and 2104 cm^–1) in the IR spectrum is probably associated with nonequivalence of the hydrogen atoms in the molecule.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 315–318, February, 1994.     

Spectroscopic characterization and crystal structure of cis-Bis(N-(2-benzoyl)-N′,N′-diphenylthioureato-k 2O,S)nickel(II)

The title compound [Ni(C₂₀H₁₅N₂OS)₂] is prepared by the reaction of metal acetate with the corresponding acylthiourea derivative. The complex is characterized by elemental analysis, IR, ¹H and ¹³C NMR, and its structure is determined by single crystal X-ray diffraction. The Ni(II) ion is coordinated by the S and O atoms of two N-benzoyl-N??,N??-diphenylthiourea ligands in a slightly distorted square-planar coordination geometry. The two O and two S atoms are mutually cis to each other. The substance crystallizes triclinic (P-1 space group) with cell dimensions a = 10.7262(9) ?, b = 12.938(3) ?, c = 14.2085(12) ?, ?? = 74.650(4)°, ?? = 78.398(4)°, ?? = 68.200(5)°, and two formula units in the unit cell. The structure is very close to the related N-(2-furoyl) Ni complex reported previously.     

Studies on the crystal structure and characterization of N-(4-acetylphenyl)-N’-(2-nitrobenzoyl)-thiourea

N-(4-acetylphenyl)-N′-(2-nitrobenzoyl)-thiourea has been synthesized in high yield under PEG-400 as the phase-transfer catalyst and its the compound structure was determined by single crystal X-ray diffraction. The compound is also a considerable plant-growth regulator. In addition, the compound L exhibited selective recognition for Hg²⁺ over other metals ions such as Ag⁺, Ca²⁺, Co²⁺, Ni²⁺, Cd²⁺, Pb²⁺, Zn²⁺, Cr³⁺, and Mg²⁺ in DMSO solutions.     

Competitive bulk liquid membrane transport of Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ag(Ⅰ),Cu(Ⅱ)and Mn(Ⅱ),cations using 2,2'-dithio(bis)benzothiazole as carrier

A series of competitive metal-ion transport experiments has been performed.Each involved transport from an aqueous source phase across an organic membrane phase into an aqueous receiving phase.The source phase contained equimolar concentration of Co（Ⅱ）,Ni（Ⅱ）,Zn（Ⅱ）,Cd（Ⅱ）,Ag（Ⅰ）,Cu（Ⅱ） and Mn（Ⅱ） metal cations.The transport experiments of metal cations were carried out by 2,2’-dithio（bis）benzothiazole（DTB） in chloroform（CHCl₃）.The source phase being buffered at range pH of 4-6.5 and receiving phase being buffered at pH 3.The obtained results show that the selectivity and the efficiency of Ag（I） transport from aqueous solutions are observed in this investigation.The effect of concentration of palmitic acid in the transport efficiency of Ag（Ⅰ） ion was also conformed.     

Synthesis and X-ray crystal structure of [1,3-bis(η5-cyclopentadienyl)-1,1,3,3-tetramethyldisiloxane]hafnium(IV) dichloride

Summary The tetramethyldisiloxane-bridged hafnocene complex [HfCl₂{-(⁵-C₅H₄)SiMe₂OSiMe₂(²-C₅H₄)}] (1) has been prepared by the reaction of HfCl₄ with the dilithiatedbis(cyclopentadienyl)disiloxane (LiC₅H₄SiMe₂)₂O in a molar ratio of 1:2. The new compound was characterized by spectroscopic and X-ray diffraction methods. The crystals are monoclinic of space groupP2₁/c and isostructural with the corresponding complexes of titanium and zirconium. The unit cell dimensions area=13.51(1) Å,b=8.672(7) Å,c=15.41(1) Å, =97.15(2)°, andZ=4.

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Darstellung und Röntgenkristallstruktur von [1,3-Bis(⁵-cyclopentadienyl)-1,1,3,3-tetramethyldisiloxan]hafnium(IV)dichlorid

Zusammenfassung Der tetramethyldisiloxan-überbrückte Hafnocenkomplex [HfCl₂{-(⁵-C₅H₄)-SiMe₂OSiMe₂(²-C₅H₄)}] (1) wurde durch Umsetzung von HfCl₄ mit dem lithiiertenBis(cyclopentadienyl)disiloxan (LiC₅H₄SiMe₂)₂O im Molverhältnis 1:2 dargestellt. Die neue Verbindung wurde spektroskopisch und röntgenographisch charakterisiert. Sie kristallisiert in der monoklinen RaumgruppeP2₁/c und ist isostrukturell mit den entsprechenden Titan-und Zirkoniumkomplexen. Die Dimensionen der Einheitszelle sinda=13.51(1) Å,b=8.672(7) Å,c=15.41(1) Å, =97.15(2)° undZ=4.

     

Synthesis and crystal structure of dioxobis(μ-pentafluorophenylimido)di-(η-methylcyclopentadienyl)dimolybdenum

The reaction between C₆F₅NO₂ and [(η-MeC₅H₄)Mo(CO)₃]₂ yields the dioxobisimido complex, [(η-MeC₅H₄)MoO (η-NC₆F₅)]₂ (1). The X-ray crystal structure of compound 1 shows a cis arrangement of the methylcyclopentadienyl ligands and a puckered metallacyclic core.     

Synthesis and structure of N,N′-bis(dihexylphosphorylmethyl)-1,4-diaminobutane

Russian Journal of General Chemistry - N,N′-Bis(dihexylphosphorylmethyl)-1,4-diaminobutane has been obtained via the Kabachnik–Fields reaction. Crystal structure of its salt with nitric...     

Synthesis of n-aminoglycosides derived from alkaloid cytisine,their biological activity and crystal structure of N-(β-D-galactopyranosyl)cytisine

Optimal conditions were found for the synthesis of a number of new N-aminoglycosides of the alkaloid cytisine, using commercially available monosaccharides, namely, D-glucose, D-galactose, D-xylose, and L-arabinose. X-ray structural analysis indicated an absolute β-anomeric configuration of N-(β-D-galactopyranosyl)cytisine in the crystalline state. The comparative cytotoxicity of cytisine and some of its N-aminoglycosides was determined.     

Relaxivity studies and X-ray structure of Gd(III)-diethylenetriamine-N,N′,N″-triacetic acid-N,N″-bis(2-methoxyphenethylamide) as a potential contrast agent for magnetic resonance imaging

A new bis(amide) derivative of diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid (H₅dtpa), diethylenetriamine-N,N′,N″-triacetic-N,N″-bis(2-methoxyphenethylamide) (H₃L), has been synthesized. The crystal structure of gadolinium(III) complex of H₃L ([GdL]) has been determined by X-ray crystallography. The coordination sphere of Gd(III) comprises three amine nitrogens, two amide oxygens, three carboxylic acid oxygens, and one water molecule. ¹⁷O NMR shifts showed that the [DyL] complex had one inner-sphere water molecule. Relaxivity studies with the gadolinium(III) complex showed that they associate strongly with proteins leading to a significant relaxivity enhancement.     

Synthesis and spectral properties of new 3,3’-bis(dipyrrolylmethene) with acetylene spacer

Bis(2,4,7,9-tetramethyl-8-ethyldipyrrolylmethen-3-yl)acetylene dihydrobromide (H₂L·2HBr), new bis(dipyrrolylmethene), in whose molecule dipyrrolylmethene domains were connected through 3,3′-carbon atoms of internal pyrrole nuclei by acetylene spacer, were synthesized by original procedure. The compound was characterized by element analysis, IR, ¹H NMR, and electronic spectroscopy. The comparative analysis of spectral properties shows the reduction of the basicity of H₂L ligand in comparison with the structural analogs, which contain internal methylene spacer. The quantum-chemical simulation showed that the rigid acetylene spacer gives linear structure to the H₂L molecule in contrast to the spiral-shaped geometry of structural analogs with -CH₂- spacer.     

Synthesis and X-ray crystal structure of oxamido-bridged heterobinuclear Ni(Ⅱ)-Cu(Ⅱ) complexes

The two complexes [Ni(oxen)Cu(L)2](ClO4)2.xH2O (L=2,2'-bipyridyl(bpy), 1,10-phenanthroline(phen)) have been synthesized, where oxen is N,N'-bis(2-aminoethyl)oxamido di-anion. The crystal structure of [Ni(oxen)Cu(bpy)2](ClO4)2.CH3OH has been determined by X-ray diffraction method. The crystal is triclinic system, space group P1 with a=12.179(1),b=12.298(2), c=11.476(2) A, a=97.57(1), B=97.52(1), 7=80.29(2), V=1669.04(67) A3, Z=2, Dcalcd=1.667 g/cm3. The structure has been refined to final R of 0.076 and Rw of 0.080, respectively. The complexes have an extended oxamido-bridged structure and consist of Ni(Ⅱ) ion in a square planar environment and Cu(Ⅱ) ion in a distorted octahedral environment.     

Synthesis,vibrational spectra,and structure of 4′-(4″-benzo-15-crown-5)oxy-2,2′:6′,2″-terpyridine (L) and its transition metal complexes. Extraction and ion-selective properties of L

Complexes of Co(II), Ni(II), Zn(II), and Cu(II) perchlorates and hexafluorophosphates with 4′-(4″-benzo-15-crown-5)oxy-2,2′:6′,2″-terpyridine (L) [M(L)₂](ClO₄)₂ · 3H₂O and [M(L)₂](PF₆)₂ · 2H₂O were synthesized. The spectral criteria of ligand coordination through the terpyridine nitrogen atoms were established. An assumption concerning the benzo-15-crown-5 conformation in the ligand molecule in the synthesized complexes was made. The extraction and ion-selective properties of L were studied.     

Synthesis and characterization of some ferrocene-containing telluroether ligands: crystal structure of 1,1′-bis(phenyltelluro)ferrocene

A series of five monodentate ferrocene tellurium ligands of the type Fe(C₅H₅)(C₅H₄TeR) and five bidentate 1,1′-disubstituted ferrocene tellurium ligands of the type Fe(C₅H₄TeR)₂ (R = Me, ⁿBu, C₆H₅, p-MeOC₆H₄, p-EtOC₆H₄) has been prepared by the reaction of 1,1′-dilithioferrocene with the appropriate ditellurides R₂Te₂. The ligands have been characterized by their elemental analyses, ¹H and ¹³C NMR spectra, mass spectra and cyclic voltammetry studies. The structure of Fe(C₅H₄TeC₆H₅)₂ has been determined by single-crystal X-ray diffraction study.     

Synthesis and crystal structure (1,10-diaza-18-crown-6-N,N′,O,O′)dichloromanganese(II)

A new crystalline complex (1,10-diaza-18-crown-6-N,N′,O,O′)dichloromanganese(II) [MnCl₂(DA18C6)] (I) is synthesized and studied by single-crystal X-ray diffraction. The structure of compound I (space group P2₁/c, a = 11.827 Å, b = 7.580 Å, c = 19.715 Å, β = 98.76°, Z = 4) is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.026 for all 3055 independent measured reflections (CAD4 automated diffractometer, λMoK _α radiation). The [MnCl₂(DA18C6)] complex molecule in I is of the host-guest type: its Mn²⁺ cation is asymmetrically arranged in the cavity of the DA18C6 ligand and coordinated by its four heteroatoms, namely, the two N atoms and two O atoms, and by the two Cl^? anions. The coordination polyhedron of the Mn²⁺ cation (six-coordination) may be described as a distorted pentagonal bipyramid with one unfilled vertex or as a distorted square pyramid with one split vertex at the two O atoms of the DA18C6 ligand. The DA18C6 ligand in I has an unusual asymmetric conformation. The complex molecules in a crystal of I are linked by a pair of N-H···Cl intermolecular hydrogen bonds into centrosymmetric dimers.     

Synthesis,crystal structure,and luminescence of a new zinc(II) coordination polymer based on 2-naphthol-5-carboxylate and 4,4′-bipyridine

To further explore the coordination possibilities of naphthalene-based carboxylic acids, a Zn^II coordination polymer, [Zn₃(L)₆(bipy)₂] _n (1), with bulky 2-naphthol-5-carboxylate (L) and bridging 4,4′-bipyridine (bipy), was synthesized and characterized. Structural analysis reveals that 1 is a 1-D polymeric chain with trinuclear units as nodes, which are further extended via interchain secondary interactions, such as O–H ··· O hydrogen-bonding and aromatic π ··· π stacking interactions, to form an overall 3-D framework. Complex 1 exhibits strong solid-state luminescence emission at room temperature, mainly originating from intraligand π→π* transition of L.     

Synthesis,characterization, and crystal structure of Ni(II) and Cu(II) complexes with N-furoyl-N′,N′-diethylthiourea: antifungal activity

The complexes cis-bis(N-furoyl-N′,N′-diethylthioureato-k ²O,S)nickel(II) and cis-bis(N-furoyl-N′,N′-diethylthioureato-k ²O,S)copper(II) were prepared by the reaction of metal acetate with the corresponding acylthiourea derivative. The complexes were characterized by IR, ¹H-NMR, ¹³C-NMR, and single-crystal X-ray diffraction. Both complexes show two furoylthiourea ligands bonded to metal to form a four-coordinate complex with square-planar geometry. The antifungal activity of the prepared complexes was studied against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides, responsible for important plant diseases.