Study of the Steric Structure of 7-Alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonan-9-ones and Their Derivatives Using 1H NMR Spectroscopy

Using the ¹H NMR spectroscopic method it has been shown that 7-alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonan-9-ones and 7-alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonanes exist in deuterochloroform solution in a double chair conformation. 7-(3-Butoxypropyl)-3-oxa-7-azabicyclo[3.3.1]nonan-9-ol is a 1:1 mixture of the two stereoisomeric alcohols. One of them exists in a double chair conformation having an equatorial hydroxyl group with relation to the piperidine ring and the other in a chair-boat conformation having an axial hydroxyl group which involves an intramolecular hydrogen bond with the unshared electron pair of the nitrogen atom.     

Spatial Structure of Isomers of 3,7-Dialkoxyalkyl-3,7-diazabicyclo[3.3.1]nonan-9-ols

The spatial structure of 3,7-dialkoxyalkyl-3,7-diazabicyclo[3.3.1]nonan-9-ols has been investigated with the aid of ¹H and ¹³C NMR spectroscopy. It was shown that the secondary alcohols studied exist in solution predominantly in a chair-boat conformation which proved to be energetically more favorable than a chair-chair conformation due to the formation of an intramolecular hydrogen bond (IMHB) between the unshared pair of electrons on the nitrogen atom and the hydrogen atom of the hydroxyl group.     

Polymerization of N,N-Dimethylaminopropyl-Acrylamide Through Hydrogen Transfer Induced by the Propagation of the Polyacrolein Anion

The anionic polymerization of acrolein (AL) with N, N-dimethylamino-propylacrylamide (DMAPA) in the presence of water was investigated in tetrahydrofuran, benzene, and ethanol at 0°C in a nitrogen atmosphere. The resulting polymers were found to be essentially vinyl polymers with one DMAPA attached and an aldehyde side chain. From observations of the polymerization process by ¹H NMR, we find that polymerization was initiated by the hydroxyl anion formed in the thermodynamic equilibrium between the amine of DMAPA and water. The hydrogen transfer reaction of DMAPA was caused by the propagating poly-AL anion. On the other hand, the monomer reactivity ratios and the Q₂-e₂values of DMAPA were determined by the free-radical copolymerization of styrene (St, M₁) with DMAPA and AIBN as initiator.     

15N NMR spectral parameters of compounds of the N-methylpyrazole series

The¹⁵N NMR chemical shifts and¹⁵N-¹H SSCCs are presented for substituted N-methylpyrazoles with substituents such as CH₃, NO₂, Br, Cl, NH₂, O=CNH₂, O=CPh, and COOH at the carbon atoms. The¹⁵N chemical shifts of the cyclic atoms of nitrogen and the nitro groups are discussed as well as the geminal and vicinal SSCCs of the ring nitrogen atoms with the hydrogen atoms of the CH and CH₃ fragments.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117334 Moscow. D. I. Mendeleev Chemico-Technological Institute, Moscow, Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2554–2561, November, 1992.     

Syntheses and structural determination of eight-coordinate Na[YbIII(Cydta)(H2O)2] · 5H2O and [YbIII(Hegta)] · 2H2O complexes

Na[Yb^III(Cydta)(H₂O)₂] · 5H₂O (1) (H₄Cydta = trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid) and [Yb^III(Hegta)] · 2H₂O (2) (H₄egta = ethyleneglycol-bis-(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) were prepared and their composition and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. Complex 1 crystallized in the triclinic crystal system with space group P 1; the Yb^III is eight-coordinate by a hexadentate Cydta and two water molecules. Complex 2 is a protonated egta complex, crystallized in the monoclinic crystal system with space group P 2 ₁ /c; Yb^III is coordinated only by the octadentate Hegta ligand. Both these complexes adopt a pseudo-square antiprismatic conformation.     

Mercury(II) cyanide complexes with alkyldiamines: solid-state/solution NMR,computational, and antimicrobial studies

Mercury cyanide complexes of alkyldiamines (1–6), [Hg(L)(CN)₂] (where L?=?en (1,2-diaminoethane), pn (1,3-diaminopropane), N-Me-en, N, N′-Me₂-en, N, N′-Et₂-en, and N, N′-ipr₂-en), have been synthesized and characterized by elemental analysis, IR, ¹³C, and ¹⁵N solution NMR in DMSO-d₆, as well as ¹³C, ¹⁵N, and ¹⁹⁹Hg solid-state NMR spectroscopy. Complexes 1 and 2 have been studied computationally, built and optimized by GAUSSIAN03 using DFT at B3LYP level with LanL2DZ basis set. Binding modes of en and bn (where bn?=?1,4-diaminobutane) toward Hg(CN)₂ are completely different. Complexes with en and pn show chelating binding to Hg(II), while bn behaves as a bridging ligand to form a polymeric structure, [Hg(CN)₂-bn]_∞ [B.A. Al-Maythalony, M. Fettouhi, M.I.M. Wazeer, A.A. Isab. Inorg. Chem. Commun., 12, 540 (2009).]. The solution ¹³C NMR of the complexes demonstrates a slight shift of the ?C≡N (0.9 to 2?ppm) and ?C–NH₂ (0.25 to 6?ppm) carbon resonances, while the other resonances are relatively unaffected. ¹⁵N labeling studies have shown involvement of alkyldiamine ligands in coordination to the metal. The principal components of the ¹³C, ¹⁵N, and ¹⁹⁹Hg shielding tensors have been determined from solid-state NMR data. Antimicrobial activity studies show that the complexes exhibit higher antibacterial activities toward various microorganisms than Hg(CN)₂.     

Synthesis, crystal structure and spectroscopic properties of two new complexes containing azido or dicyanamido bridges

Two new complexes, [Cu(L₁){N(CN)₂}]·ClO₄ (1) (L₁ is 1,8-dimethyl-1,3,6,8,10,13-hexa-azacyclotetradecane) and [Co(L₂)(N₃)₂]·ClO₄ (2) (L₂ is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradecane) have been synthesized and characterized. The compounds crystallize in the monoclinic system P2₁ space group for 1 and P2₁/n for 2. Single crystal X-ray analysis reveals that the compound 1 assumes a one-dimensional structure via hydrogen-bonding interactions, in which each Cu(II) ion is coordinated by four nitrogen atoms from ligand L₁ and one nitrogen atom from [N(CN)₂]⁻ anion. For compound 2, each Co(III) ion is coordinated by four nitrogen atoms of ligand L₂ and two nitrogen atoms from N₃ ⁻ anion.     

Syntheses,structural determination,and binding studies of nine-coordinate multinuclear (mnH)2[EuIII(egta)]2·6H2O and binuclear (mnH)4[EuIII2(dtpa)2]·6H2O

Two lanthanide complexes, (mnH)₂[Eu^III(egta)]₂·6H₂O (1) (H₄egta = ethyleneglycol-bis-(2aminoethylether)-N,N,N′,N′-tetraacetic acid) and (mnH)₄[Eu^III₂(dtpa)₂]·6H₂O (2) (H₅dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), have been synthesized and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction reveals that 1 is multinuclear nine-coordinate and crystallizes in the monoclinic crystal system with space group C2/c. The obtained cell dimensions are a = 38.513(3)?Å, b = 13.5877(8)?Å, c = 8.7051(5)?Å, β = 99.6780(10)°, and 4490.6(5)?ų. Each methylamine (mnH⁺) cation in 1, through hydrogen bonds, connects three adjacent [Eu^III(egta)]^? anions. The [Eu^III(egta)]^? anions connect one another forming a 1-D multinuclear zigzag chain structure along the c-axis. Complex 2 is nine-coordinate binuclear structure with tricapped trigonal prismatic conformation and crystallizing in the monoclinic crystal system, but with space group P2₁/n. The obtained cell dimensions are a = 9.9132(8)?Å, b = 24.1027(18)?Å, c = 10.7120(10)?Å, β = 109.1220(10)°, and 2418.2(3)?ų. For 2, there are two kinds of methylamine cations (mnH⁺) connecting [Eu^III₂(dtpa)₂]^4? complex anions and lattice waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure.     

The Synthesis of Some New Sulfur-Bearing Various Heterocyclic Systems Derived from Asymmetrical N,N′-Disubstituted Thiourea Derivatives

The heterocyclization of an asymmetrical N,N′-disubstituted thiourea (1a–d) in ring closure reactions with Br₂/AcOH, ethyl chloroacetate, diethyl oxalate, diethyl malonate, and hydrazine hydrate led to the direct formation of sulfur-bearing various heterocyclic systems (2–8) in which the thiaenolization is toward the aryl group. The synthetic work and reactivity investigations have been well supported by standard modern spectroscopic techniques (IR, ¹ H NMR, ¹³ C NMR, mass spectrum, and microanalysis).     

Cadmium(II) complexes with phosphine tellurides: synthesis and multinuclear (31P, 125Te,and 113Cd) NMR characterization in solution

New cadmium(II) complexes with phosphine telluride ligands of the type CdX₂(R₃PTe)_n [X?=?ClO₄^?, n?=?4: R?=?n-Bu (1), Me₂?N (2), C₅H₁₀?N (3), C₄H₈?N (4) or OC₄H₈?N (5); X?=?Cl^–, n?=?2: R?=?n-Bu (6), Me₂?N (7), C₅H₁₀?N (8), C₄H₈?N (9) or OC₄H₈?N (10)] have been synthesized and characterized by elemental analyses, IR and multinuclear (³¹P, ¹²⁵Te, and ¹¹³Cd) NMR spectroscopy. In particular, the solution structures of these complexes were confirmed by ¹¹³Cd NMR at low temperature, which displays a quintuplet for each of the perchlorate complexes and a triplet for each of the chloride complexes due to coupling with four and two equivalent phosphorus atoms, respectively, indicating a four-coordinate tetrahedral geometry for the metal center. These multiplet features were further accompanied by one bond Te–Cd couplings, clearly showing that the ligand is coordinated to the metal through tellurium. The results are discussed and compared with those obtained for closely related phosphine chalcogenide analogs.     

Crystal structure of (N,N,N′,N′-tetramethyl-1,2-diaminoethane)(1,1,1-trifluoro-6-methyl-2,4-heptanedionato)copper(II) perchlorate

The solvatochromic compound [Cu(tfmh)Me₄en]ClO₄ (tfmh^? denotes the anion of 1,1,1-trifluoro-6-methyl-2,4-heptanedione) was prepared and its structure has been determined from three-dimensional X-ray diffraction data. The structure consists of discrete [Cu(tfmh)Me₄en]⁺ monomeric units and perchlorate ions. The copper(II) ion is surrounded by the two nitrogen atoms of the diamine molecule and the two oxygen atoms of the β-dionato anion. The N,N,N′,N′-tetramethyl-1,2-diaminoethane, Me₄en, coordinates as bidentate ligand through the nitrogen atoms and adopts the gauche conformation and λ configuration. The CuN₂O₂ chromophore is virtually planar. The compound crystallizes in the monoclinic system (space group P2₁/c) with a = 11.9520(2), b = 14.6600(2), c = 17.2240(4) Å, β = 135.72(2)°, Z = 4 and V = 2107.01(7) ų.     

1H, 13C, 15N NMR and X-Ray Diffractometry in Structural Studies of Macrocyclic Lactams Containing Pyridine Moiety

Abstract

We examined complexing sites of the Pb²⁺ complex of the macrocyclic lactam 1 using ¹⁵N NMR and other spectroscopies and we have found that the amide groups undergo conformational changes to allow the complexation process to proceed via the pyridine nitrogen atom and carbonyl and ethereal oxygen atoms. X-Ray analysis of compound 1 was carried out successfully. Space group I4₁/a, a=28.332(4)Å, b=28.332(4)Å, c=10.7379(4)Å, Z=16, V=8619.3(18)ų, D_c=1.197gcm^?3, R1=0.0479 (based on 2510 reflections I>2[sgrave](I). It shows presence of intramolecular hydrogen bonds, which are broken during the complexation. Molecules form supramolecular tetragonal assemblies in the crystal, which form channels the walls of which are 7.42 Å apart.     

Bis(Tetramethylselenophosphoramidoyl) Methylamine Complexes of Cd(Ii) and Zn(Ii): Synthesis and Multinuclear (31P, 77Se,and 113Cd) Nmr Characterization in Solution

Abstract

Five new complexes ZnL₂(ClO₄)₂ (1), CdL₂(ClO₄)₂ (2), CdL₂(BF₄)₂ (3), CdLCl₂ (4), and CdL(NO₃)₂ (5) [L = ((Me₂N)₂PSe)₂NMe] have been synthesized and characterized by elemental analysis, infrared (IR) and multinuclear (³¹P, ⁷⁷Se, and ¹¹³Cd), and nuclear magnetic resonance (NMR) spectroscopy. The ³¹P and ⁷⁷Se NMR data showed that the title ligand is coordinated in a bidentate fashion to the metal center via its both P=Se groups. The solution structure of the cadmium complexes was further confirmed by its ¹¹³Cd NMR spectra, which displayed a quintuplet for the perchlorate complex and a triplet for each of the nitrate and chloride complexes, respectively due to coupling with four (two ligands) and two (one ligand) equivalent phosphorus nuclei, consistent with a four-coordinate tetrahedral geometry for the cadmium center. The results are discussed and compared with the corresponding oxo and thio analogues.     

13C, 15N and 113Cd NMR and Molecular Orbital Studies of Novel Bile Acid N-(2-aminoethyl)amides and Their Cd2+-complexes

Lithocholic acid N-(2-aminoethyl)amide (1) and deoxycholic acid N-(2-aminoethyl)amide(2) have been prepared and characterized by¹H, ¹³C and ¹⁵N NMR. The accurate molecular masses of 1 and 2 have been determined by ESI MS. The formation of the Cd²⁺-complexes (1+Cd and 2+Cd) in CD₃OD solution have been detected by ¹H,¹³C, ¹⁵N and ¹¹³Cd NMR. The ¹³C NMR chemical shift assignments of 1 and 2 and their Cd²⁺-complexes are based on DEPT-135 and z-GS ¹H,¹³C HMQC experiments as well as comparison with the assignments of the related structures. The ¹⁵N NMR chemical shiftassignments of the ligands and theirCd²⁺-complexes are based on z-GS¹H,¹⁵N HMBC experiments. ¹³C NMR chemical shift differences between 1and its 1:1 Cd²⁺-complex based on ab initiocalculations at Hartree-Fock SCI-PCM level using3-21G(d) basis set are in agreement with theexperimental shift changes observed onCd²⁺-complexation.     

Syntheses and structural determination of binuclear nine-coordinate (NH4)4[SmIII2(Httha)2]·16H2O and 2-D ladder-like binuclear nine-coordinate (NH4)4[SmIII2(dtpa)2]·10H2O

Two rare-earth metal coordination compounds, (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) (H₆ttha?=?triethylenetetramine-N,N,N′,N′′,N′′′,N′′′-hexaacetic acid) and (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O (2) (H₅dtpa?=?diethylenetriamine-N,N,N′,N′′,N′′-pentaacetic acid), have been synthesized through reflux and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction techniques. Sm^III of (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) is nine-coordinate, forming tricapped trigonal prismatic coordination with three amine nitrogens and six oxygens, in which four oxygens are from one ttha and two from the other ttha. (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) crystallizes in the monoclinic crystal system with P2(1)/c space group. The crystal data are: a?=?13.9340(13) Å, b?=?22.890(3) Å, c?=?20.708(2) (14) Å, β?=?99.521(2)°, and V?=?6513.7(13) ų. There are two –NH⁺– groups in the [Sm^III₂(Httha)₂]^4?. The polymeric (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O (2) also is nine-coordinate with tricapped trigonal prismatic conformation and crystallizes in the triclinic crystal system with P–1 space group. The cell dimensions are: a?=?9.8240(8) Å, b?=?10.0329(9) Å, c?=?13.0941(11) Å, β?=?77.1640(10)°, and V?=?1227.30(18) ų. In (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O, there are two types of ammonium cations, which connect [Sm^III₂(dtpa)₂]^4? and lattice water through hydrogen bonds, leading to a 2-D ladder-like layer structure.     

A CARBON-13 NMR STUDY OF POLAR-(NITRO)TRIMETHYLENEDIAMINE-N,N,N′-TRIACETATOCOBALTATE(III) ION

Abstract

The complex ion [Co(1,3-pd3a)NO₂]^? (pd3a=trimethylenediamine-N,N,N′-triacetate ion) was prepared from equatorial-skew-[Co(1,3-pd3a)H₂ O]. The absorption spectrum and the ¹³C NMR spectrum show the nitro product to be a polar isomer. The diamine backbone ring is believed to have the chair conformation.     

C?H···N and C?H···O intramolecular hydrogen bonding effects in the 1H, 13C and 15 N NMR spectra of the configurational isomers of 1‐vinylpyrrole‐2‐carbaldehyde oxime substantiated by DFT calculations

According to the ¹H, ¹³C and ¹⁵N NMR spectroscopic data and DFT calculations, the E‐isomer of 1‐vinylpyrrole‐2‐carbaldehyde adopts preferable conformation with the anti‐orientation of the vinyl group relative to the carbaldehyde oxime group and with the syn‐arrangement of the carbaldehyde oxime group with reference to the pyrrole ring. This conformation is stabilized by the C? H···N intramolecular hydrogen bond between the α‐hydrogen of the vinyl group and the oxime group nitrogen, which causes a pronounced high‐frequency shift of the α‐hydrogen signal in ¹H NMR (～0.5 ppm) and an increase in the corresponding one‐bond ¹³C–¹H coupling constant (ca 4 Hz). In the Z‐isomer, the carbaldehyde oxime group turns to the anti‐position with respect to the pyrrole ring. The C? H···O intramolecular hydrogen bond between the H‐3 hydrogen of the pyrrole ring and the oxime group oxygen is realized in this case. Due to such hydrogen bonding, the H‐3 hydrogen resonance is shifted to a higher frequency by about 1 ppm and the one‐bond ¹³C–¹H coupling constant for this proton increases by ～5 Hz. Copyright © 2008 John Wiley & Sons, Ltd.     

Syntheses,structural determination,and binding studies of nine-coordinate mononuclear (mnH)2[DyIII(Httha)]·3H2O and (enH2)3[DyIII(ttha)]2·9H2O

Two dysprosium coordination compounds, (mnH)₂[Dy^III(Httha)]·3H₂O (1) (H₆ttha?=?triethylenetetramine-N,N,N′,N″,N′′′,N′′′-hexaacetic acid and mn?=?methylamine) and (enH₂)₃[Dy^III(ttha)]₂·9H₂O (2) (en?=?ethylenediamine), were synthesized through direct heating and characterized by elemental analysis, FT-IR, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction analysis displays that 1 is a mononuclear nine-coordinate complex with a pseudo-monocapped square antiprismatic conformation (MCSAP) crystallizing in the monoclinic crystal system with P2(1)/c space group. The crystal data are as follows: a?=?16.1363(19)?Å, b?=?13.9336(11)?Å, c?=?13.6619(14)?Å, β?=?102.2490(10)°, and V?=?3001.8(5)?ų. There are two kinds of methylamine cation in 1. They connect [Dy^III(Httha)]^2?and crystal waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure. The polymeric 2 also is a nine-coordinate structure with a pseudo-MCSAP crystallizing in the monoclinic crystal system with P2/c space group. The cell dimensions are: a?=?17.7801(16)?Å, b?=?9.7035(10)?Å, c?=?22.096(2)?Å, β?=?118.874(2)°, and V?=?3338.3(6)?ų. In 2 there are also two types of ethylenediamine cations. One connects three adjacent [Dy^III(ttha)]^3? complex anions through hydrogen bonds and the other is symmetrical forming hydrogen bonds with two neighboring [Dy^III(ttha)]^3? complex anions. These hydrogen bonds result in formation of a 2-D ladder-like layer structure as well.     

The structure of angustifoline,an alkaloid ofLupinus angustifolius,in solution

Summary The¹H and¹³C NMR spectra of the lupin alkaloidangustifoline 1 in four solvents (cyclohexane-d₁₂, CDCl₃, CD₃CN, and C₆D₆) were assigned using 2D H,H and H,C COSY and 2D J-resolved spectra. The torsional HCCH angles calculated from the vicinalJ _HH coupling constants are essentially in agreement with those expected for the deformed all-chair conformation withendo oriented N(12)-H bond, reported earlier for1 in the solid state. Some arguments seem to point, however, to a small contribution of other conformations: with ring A deformed in another direction, deformed all-chair withexo oriented N(12)-H bond and/or a conformation with ring C in the boat form.Lupin Alkaloids, part 7     

Synthesis and Structure of MnCl2(HDpyF) (HDpyF = N,N′‐di(2‐pyridyl)formamidine): New Crystallographic Disorder and Bonding Mode of the HDpyF Ligand

The reaction of N,N′‐di(2‐pyridyl)formamidine (HDpyF) with MnCl₂‐4H₂O afforded the complex MnCl₂(HDpyF), which was characterized by X‐ray crystallography. The HDpyF ligand chelates to the Mn(II) center through the first and the third nitrogen atoms to form a six‐membered ring, leaving the second and the fourth nitrogen atoms uncoordinated. The HDpyF ligand is crystallographically disordered such that two different molecules can be solved. The neutral HDpyF ligand adopts the new s‐cis‐syn‐s‐trans conformation.