Experimental and theoretical study of N-(2-hydroxyethyl)morpholine betaine

N-(2-hydroxyethyl)morpholine betaine (HEMB) has been characterized by a single crystal X-ray analysis, FTIR spectroscopy and DFT calculations. The crystals are monoclinic, space group P2₁/c with a=10.273(2), b=9.360(2), c=9.447(2) Å and β=104.72(3)Å. Two molecules of HEMB form a centrosymmetric dimer (X2) connected by a pair of hydrogen bonds between the CH₂CH₂OH and COO⁻ groups, with the O?O distance of 2.672(2) Å. The morpholine ring adopts a chair conformation with the CH₂CH₂OH group in the axial and the CH₂COO⁻ group in the equatorial position. The structures of the dimer, B2, and two monomers, B1a and B1b, have been optimized by the B3LYP approach using the 6-31G(d,p) basis set. The computed structure of B2, agrees well with the experimental X2. From two stable monomeric conformers the more favored is B1a, with the intramolecular hydrogen bond with the O-H?O distance of 2.566 Å. The effects of hydrogen bonding and electrostatic interactions on the conformation of the molecules investigated have been discussed. The FTIR spectrum shows a broad absorption in the 3300-2600 cm⁻¹ region, typical of moderate O-H?O hydrogen bonds.     

C CP MAS NMR, FTIR, X-ray diffraction and PM3 studies of some N-(ω-carboxyalkyl)morpholine hydrohalides

N-(ω-carboxyalkyl)morpholine hydrochlorides, OC₄H₈N(CH₂)_nCOOH·HCl, n=1–5, were obtained and analyzed by ¹³C cross polarization (CP) magic angle spinning (MAS) NMR, FTIR and PM3 calculations. The structure of N-(3-carboxypropyl)morpholine hydrochloride (n=3) has been solved by X-ray diffraction method at 100 K and refined to the R=0.031. The crystals are monoclinic, space group P2₁/c, a=14.307(3), b=9.879(2), c=7.166(1) Å, β=93.20(3)°, V=1011.3(3) ų, Z=4. In this compound the nitrogen atom is protonated and two molecules form a centrosymmetric dimer, connected by two N⁺–HCl⁻ (3.095(1) Å) and two O–HCl⁻ (3.003(1) Å) hydrogen bonds. ¹³C CP MAS NMR spectra, contrary to the solution, showed non-equivalence of the ring carbon atoms. The PM3 calculations predict a molecular dimer without proton transfer for an HCl complex, while for an HBr complex an ion pairs with proton transfer, and reproduces correctly the conformation of both dimers but overestimates H-bond distances. Shielding constants calculated from the PM3 geometry of ion pairs gave a linear correlation with the ¹³C chemical shifts in solids.     

Hydrogen Bonding Complexes of Poly(styrene-co-2-hydroxyethyl acrylate) and Poly (styrene-co-4-vinylpyridine)

Summary: Random copolymers of poly(styrene-co-4-vinylpyridine) (S4VP) and poly (styrene-co-2-hydroxyethyl acrylate) (SHEA) of different compositions were prepared and characterized. An investigation of the effects of solvent and densities of the interacting species incorporated within these copolymers showed that novel and various hydrogen bonding interpolymer complexes of different structures were elaborated when these copolymers are mixed together. The specific interactions that occurred within the SHEA copolymers and the elaborated complexes were evidenced by FTIR qualitatively from the appearance of a new band at 1604 cm⁻¹ and quantitatively using appropriate spectral curve fitting in the carbonyl and pyridine regions. The intermolecular hydrogen bonding interactions that occurred between the hydroxyl groups of the SHEA and the nitrogen atom of the pyridine groups in the S4VP are stronger than the self-associations within the SHEA. In the solid state, a DSC analysis showed that the variation of the glass transition temperatures of these materials with the composition behaved differently with the densities of interacting species and were analyzed quantitatively. A thermal stability study of the synthesized copolymers and of their different mixtures carried by thermogravimetry confirmed a similar behaviour.     

The influence of charges and hydrogen bond on the conformation of zwitterionic 3-(2-hydroxyalkyl-pyridinium)-propionates and their hydrobromides

The effects of intra- and intermolecular electrostatic interactions and hydrogen bonding on the conformation of 3-(2-hydroxymethyl-pyridinium)-propionic acid bromide (1) and 3-(2-hydroxyethyl-pyridinium)-propionic acid bromide (2) have been studied. In 1, the molecules are linked by Br⁻ ion to form two intermolecular hydrogen bonds COOHBrHOCH₂ (O(1)Br=3.175(3) and O(3)Br=3.305(3) Å) yielding chains. The molecules of 2 form centrosymmetric dimers connected by a pair of H-bonds between COOH and CH₂OH groups (O(1)O(3)=2.674(3) Å), and the H-bonded CH₂OH group further interacts with the Br⁻ ion (O(3)Br=3.166(5) Å). In both the compounds, the Br⁻ ion additionally interacts electrostatically with the positively charged nitrogen atom. To analyse these interactions theoretically, the structures of 3-(2-hydroxy-alkyl)pyridinium propionates (betaines) and their hydrogen bromides as monomers and dimers in various configurations are analysed by PM3 and B3LYP/6-31G(d,p) calculations. Although both electrostatic interactions and H-bonds strongly affect the conformation of the investigated compounds, the former effect seems to be dominant. FTIR spectra of 1 and 2 in the solid state are analysed.     

Ab initio study of 1,1-(methylphosphinylidene) bis(methanamine) and vibrational assignment of its N,N′-coordinated Pt(II) and Pd(II) chloro complexes

Infrared and Raman spectra of 1,1-(methylphosphinylidene) bis(methanamine) [mpbm, (CH₃)PO(CH₂NH₂)₂] and its N,N′-coordinated Pt(II) and Pd(II) have been studied in the 4000–200 cm⁻¹ frequency range. Ab initio calculations have been carried out for different conformations of the mpbm at HF/6-31G* level of the theory from which structural parameters, conformational stability and predicted infrared and Raman spectra have been obtained. A complete vibrational assignment of the lowest energy conformer, tttg⁻, as well as of its N,N′-coordinated Pt(II) and Pd(II) chloro-complexes was done on the basis of the calculated frequencies, relative infrared intensities, Raman activities and potential energy distribution (PED). The theoretical predictions are compared with the experimental results where appropriate.     

Synthesis, crystal and molecular structures, and steroechemical nonrigidity ofN-(chlorodimethylgermylmethyl)-andN-(bromodimethylgermylmethyl)-N-[(S)-1-phenylethyl]acetamides andN-(chlorodimethylgermylmethyl)-4-phenyl-2-pyrrolidone

RacemicN-(chlorodimethylgermylmethyl)-4-phenyl-2-pyrrolidone and the first optically active amide derivatives containing the asymmetrical carbon atom and the five-coordinate germanium atom,viz.,N-(chlorodimethylgermylmethyl)- andN-(bromodimethylgermyl-methyl)-N-[(S)-1-phenylethyl] acetamides, were synthesized. Their structures were established by X-ray diffraction analysis. The geometric characteristics of the trigonal-bipyramidal valence environment about the germanium atoms are compared with those of analogous enantiomeric silicon compounds and the related five-coordinate germanium compounds. The barriers to permutational isomerization of the title compounds were determined by dynamic¹H NMR spectroscopy. It was found that these barriers are higher than those of the corresponding silicon analogs. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 137–144, January, 2000.     

X-Ray, MP2 and DFT studies of the structure and vibrational spectra of homarinium chloride

The effects of hydrogen bonding, inter- and intramolecular electrostatic interactions on the structure of homarinium chloride, HOMH·Cl, in the crystal and its isolated molecule have been studied by X-ray diffraction, FT-IR, Raman, ¹H and ¹³C NMR spectroscopies, and by the MP2 and DFT theoretical methods. In the crystal, the Cl⁻ anion is connected with protonated homarine via the O–HCl⁻ hydrogen bond of the length of 2.937(4) Å, and two N⁺Cl⁻ intermolecular electrostatic interactions. In the isolated molecule, according to the MP2 and B3LYP calculations, the Cl⁻ anion is engaged in a shorter hydrogen bond (O–HCl⁻ of 2.811–2.861 Å) and in one type of intramolecular electrostatic interactions. The calculated bond lengths and bond angles at the MP2 and B3LYP levels of theory are in good agreement with the X-ray data, except the conformation of the COOH group, which is cis (syn) in the crystal and trans (anti) in the isolated molecule. The tentative assignments for the experimental solid state vibrational spectra of HOMH·Cl and HOMD·Cl have been made on the basis of the B3LYP/6-31G(d,p) calculated frequencies and intensities. The effect of quaternization of picolinic acid on the chemical shifts of the ring protons and carbons is analyzed.     

N,N-二(2-羟乙基)氨甲基膦酸二乙酯的合成

改进了非卤反应型阻燃剂N,N-二(2-羟基乙基)氨甲基膦酸二乙酯(BHAPE)的合成方法.在35℃左右将二乙醇胺滴入37%~40%的甲醛水溶液中,加毕,于40~45℃继续保温反应2 h,然后于80~82℃,小于0.094 MPa,减压蒸馏直到没有馏分为止,得到中间体3-(2-羟基乙基)-1,3-氧氮杂环戊烷(HENH).向HENH中加入阳离子交换树脂催化剂,于55~62℃滴入亚磷酸二乙酯,加毕,于60~62℃保温反应2 h,降到室温,过滤回收催化剂,得黄色透明液体产品,收率98.5%.用元素分析、红外光谱和核磁共振谱表征了中间体和标题化合物.     

Crystal and molecular structure, hydrogen bonding and electrostatic interactions of bis(pyridine betaine) perchlorate

Bis(pyridine betaine) perchlorate, (PB)₂H·ClO₄, has been characterized by X-ray diffraction, B3LYP and MP2 calculations, FTIR, Raman and NMR spectroscopy and DSC. The complex crystallizes in space group C2/c. A pair of PB molecules is bridged by a short symmetric O·H·O hydrogen bond of the length 2.456(5) Å. Three conformers (I-III), with respect to the N⁺?O distances, of (PB)₂H cation have been analyzed at the DFT and MP2 level of theory and compared with the C(1)?O distances in the (PhCH₂COO)₂H anion. The calculated O?O distances for the analyzed cations are slightly shorter than that in the crystal. The type of hydrogen bond depends on the cation conformation and the method of calculations. The FTIR spectra of (PB)₂H·ClO₄ and (PBd₅)₂H·ClO₄ (bis(pyridine-d₅ betaine) perchlorate) show a broad and intense absorption in the 1500-400 cm⁻¹ range, which is similar to the type A acid salts of carboxylic acids and other 2:1 betaine complexes with mineral acids. In the Raman and second FTIR-derivative spectra (d²) the broad absorption is absent. A linear unit-slope correlation between d² negative band and Raman band is found. This confirms that derivative spectrometry can be used to estimate frequencies of the narrow bands covered by the broad absorption due to the O·H·O stretching and bending vibrations.     

Crystal structures of cobalt(II) complexes with N-(2-hydroxyethyl)iminodiacetic and N,N-bis(2-carbamoylethyl)aminoacetic acids: Co(Heida)·2H2O and Co(Bcegly)(ClO4)·2H2O

The cobalt atom in the structures studied is situated in the center of an octahedron involving donor atoms N and 3O organic ligands Heida or Bcegly (ions of hydroxyethyliminodiacetate or bis(carbamoylethyl)aminoacetate, respectively), water molecule oxygen atom, and a carboxylic atom of the neighboring ligand in the trans-position to the N atom, so that each (II) ion is linked with two organic anions. This results in a formation of infinite chains — uncharged [Co(Heida)(H₂O)]_n or cationic {[Co(Bcegly)(H₂O)]⁺}_n. In both cases, a molecule of crystallization water is present, and in the second case, the charge of the chains is compensated by perchlorate ions. Aminoacetic cycle of the Heida ligand is approximately coplanar to another such cycle, while a similar cycle of the Bcegly ligand is in the plane of one of six-membered aminopropionamide cycles.     

2-(3-羟基-2-吡啶基)-苯并咪唑的合成、晶体结构及光谱研究

在合成2-(3-羟基-2-吡啶基)-苯并咪唑的基础上, 利用NMR (1H, 13C, COSY, HSQC 和HMBC), MS, IR 和UV 进
行了详细表征; 通过X-ray 单晶衍射测定该化合物的晶体结构, 实验结果表明该晶体属于单斜晶系{空间群为P21/c,
a＝14.289(3) Å, b＝10.618(2) Å, c＝12.783(3) Å, β＝93.51(3)°, V＝1935.8(7) Å3, Z＝8}, 很好支持了波谱表征的结果.
2-(3-羟基-2-吡啶基)-苯并咪唑的荧光光谱表明, 该化合物在激发态下存在双质子转移现象, 密度泛函计算结果合理解
释了实验现象.     

Semi-Empirical and DFT Studies on Structures and Spectra for C78（CH2）2

Eighteen possible isomers of C78（CH2）2 weTe investigated by the INDO method. It was indicated that the most stable isomer was 42,43,62,63-C78（CH2）2, where the -CH2 groups were added to the 6/6 bonds located at the same hexagon passed by the longest axis of C78 （C2v）, to form cyclopropane structures. Based on the most stable four geometries of C78（CH2）2 optimized at B3LYP/3-21G level, the first absorptions in the electronic spectra calculated with the INDO/CIS method and the IR frequencies of the C-C bonds on the carbon cage computed using the AM1 method were blue-shifted compared with those of C78 （C2v） because of the bigger LUMO-HOMO energy gap and the less conjugated carbon cage after the addition. The chemical shifts of ^13C NMR for the carbon atoms on the added bonds calculated at B3LYP/3-21G level were moved upfield thanks to the conversion from sp^2-C to sp^3-C.     

Reaction of 2-Chloro-5-(chloromethyl)thiophene with Monoethanolamine Vinyl Ether

At the alkylation of monoethanolamine vinyl ether with 2-chloro-5-(chloromethyl)thiophene in ethyl alcohol (60-70°C) a product of disubstitution and transvinylation, viz. N,N-bis(5-chloro-2-thienylmethyl)-N-(2-hydroxyethyl)ammonium chloride is formed. The analogous reaction in the absence of solvent proceeds with the formation of N-(5-chloro-2-thienylmethyl)-N-(2-vinyloxyethyl)amine.     

Crystal and molecular structure of (1S,2S,4aS, 8aS)-N-(N-allyldiaminomethanethione)-1-(2-hydroxy-2,5,5,8a-tetramethyldecahydronaphthalenyl) acetamide

Crystal and molecular structure of a new homodrimanic compound (1S,2S,4aS, 8aS)-N-(N-allyldiaminomethanethione)-1-(2-hydroxy-2,5,5,8a-tetramethyldecahydronaphthalenyl) acetamide has been determined by X-ray diffraction analysis. The crystal is monoclinic, unit cell parameters are: a = 9.577(2) Å, b = 7.414(1) Å, c = 16.856(3) Å; β = 94.83(3)°, space group P2₁, Z = 2, of composition C₂₀H₃₅N₃O₂S. Two cyclohexan fragments have ordinary structure and chair-configuration typical of this compound class in homodrimanic skeleton. Ethanol molecule is located in the outer sphere. The withdrawal of carbon atoms from planar fragments of cyclohexan rings varies within the limits from 0.722(5) Å to − 0.634(5) Å. A dihedral angle between the mean-square planes of the latter equals 16.0(2)°, torsion angle (5)-(5)-(10)-(16) 171.0(1)° indicates their trans-joint. In the side non linear chain allyl group is connected to terminal nitrogen atom of thiosemicarbazide molecule. Intermolecular hydrogen bonds between carbonyl atom of acetamide fragment, ethanol molecule, and donor-acceptor groups of thiosemicarbazide moiety play the main part in crystal structure organization. Original Russian Text Copyright ? 2005 by E. P. Styngach, S. T. Malinovskii, L. P. Bets, L. A. Vlad, M. Gdanets, and F. Z. Makaev __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 4, pp.785–789, July–August, 2005.     

[2-(N,N-Dimethylaminomethyl)ferrocenyl] as a ligand towards mercury

The diorganomercurial bis[2-(N,N-dimethylaminomethyl)ferrocenyl]mercury(II), (FcN)₂Hg (3), can be obtained by the symmetrisation of the heteroleptic (FcN)HgCl (2) with Na₂S₂O₃ or in the transmetallation reaction of 2 with (FcN)Li. By crystallisation only the crystals of rac-(FcN)₂Hg were obtained. X-ray diffraction analysis revealed linear coordinated mercury atom with two η¹-bonded FcN ligands. Additionally, weak chelate interactions exist between mercury and nitrogen atoms of the ---CH₂NMe₂ side chains. According to the ¹H-NMR findings, these interactions are not preserved in solution. Diorganomercurial 3 appears in solution as a mixture of two diastereomers with rac/meso-(FcN)₂Hg ratio of 1:1. This diastereomeric ratio in solution remains constant within a wide temperature range and in different solvents. The NMR spectroscopic data of the heteroleptic organomercurials [(FcN)HgCl]₂·H₂O (1) and (FcN)HgCl (2) indicate the chelate-free structure of this compounds in solution within the studied temperature interval (−80 to 90 °C).     

Cyano-complexes and salts with tetracyanonickellateII and N,N-bis(2-hydroxyethyl)-ethylenediamine: synthesis,IR spectra,magnetic properties,thermal analyses,and crystal structures

Four cyano complexes, [Ni(N-bishydeten)Ni(CN)₄] _n (c1), [Cu(N-bishydeten)₂][Ni(CN)₄] (c2), [Zn₂(N-bishydeten)₂Ni(CN)₄] _n (c3), and [Cd(N-bishydeten)₂][Ni(CN)₄] (c4), have been synthesized and characterized by FT-IR, elemental, and thermal analyses. The structures of c2 and c4 were determined by single-crystal X-ray diffraction studies; both structures contain isolated cations and anions. The c2 consists of [Cu(N-bishydeten)₂]²⁺ with octahedrally coordinated Cu^II and diamagnetic [Ni(CN)₄]^2–, but c4 consists of [Cd(N-bishydeten)₂]²⁺, in which Cd^II is eight coordinate with two tetradentate N-bishydeten and diamagnetic [Ni(CN)₄]^2–. The value of the shape measure S (^o) indicates that the coordination geometry around Cd^II lies along D _2d [dodecahedron; (dd)], C _2v [bicapped trigonal prism; (btp)], and D _4d [square antiprism; (sap)] but close to D _2d and D _4d. Variable temperature magnetic susceptibility measurements of c1 and c2 show the presence of little antiferromagnetic interaction below 20?K. Thermal analyses reveal that first neutral N-bishydeten and then cyano ligands were liberated from the complexes.     

Synthesis,characterization, structures,and DFT study of zinc(II) complexes with tributylphosphine chalcogenides

Four new zinc(II) complexes of the type [ZnCl₂(n-Bu₃PE)₂] (E=O (1), S (2), Se (3), or Te (4)) have been synthesized from zinc(II) chloride and the ligands n-Bu₃PE giving yields of 56–88%. The adducts were characterized by multinuclear (³¹P, ¹³C, and ⁷⁷Se) NMR, conductivity, IR spectroscopy and by X-ray analyses. Zinc complexes 1–4 are compriseS of two ligands coordinated to the metal center in a distorted tetrahedral arrangement. The P=E bond lengths of 1.497(7) (E=O), 2.000(4) (E=S), and 2.178(2) Å (E=Se) in these complexes are slightly elongated compared to those in the free ligand. In addition, a DFT/B3LYP theoretical study on the geometry optimization of the title ligands and their zinc complexes has been carried out in order to support and complement the experimental data and to further investigate the nature of the chalcogenide-metal interaction. The results show good agreement between the experimental and theoretical data.     

Structural and spectral studies of N-2-(pyridyl)-, N-2-(3-, 4-, 5-, and 6-picolyl)- and N-2-(4,6-lutidyl)-N′-2-thiomethoxyphenylthioureas

Structures of the following compounds have been obtained: N-(2-pyridyl)-N′-2-thiomethoxyphenylthiourea, PyTu2SMe, monoclinic, P2₁/c, a=11.905(3), b=4.7660(8), c=23,532(6) Å, β=95.993(8)°, V=1327.9(5) ų and Z=4; N-2-(3-picolyl)-N′-2-thiomethoxyphenyl-thiourea, 3PicTu2SeMe, monoclinic, C2/c, a=22.870(5), b=7.564(1), c=16.941(4) Å, β=98.300(6)°, V=2899.9(9) ų and Z=8; N-2-(4-picolyl)-N′-2-thiomethoxyphenylthiourea, 4PicTu2SMe, monoclinic P2₁/a, a=9.44(5), b=18.18(7), c=8.376(12) Å, β=91.62(5)°, V=1437(1) ų and Z=4; N-2-(5-picolyl)-N′-2-thiomethoxyphenylthiourea, 5PicTu2SMe, monoclinic, C2/c, a=21.807(2), b=7.5940(9), c=17.500(2) Å, β=93.267(6)°, V=2893.3(5) ų and Z=8; N-2-(6-picolyl)-N′-2-thiomethoxyphenylthiourea, 6PicTu2SMe, monoclinic, P2₁/c, a=8.499(4), b=7.819(2), c=22.291(8) Å, β=90.73(3)°, V=1481.2(9) ų and Z=4 and N-2-(4,6-lutidyl)-N′-2-thiomethoxyphenyl-thiourea, 4,6LutTu2SMe, monoclinic, P2₁/c, a=11.621(1), b=9.324(1), c=14.604(1) Å, β=96.378(4)°, V=1572.4(2) ų and Z=4. Comparisons with other N-2-pyridyl-N′-arylthioureas having substituents in the 2-position of the aryl ring are included.     

Synthesis of chiral lithium carbamates from (S)-2-(N,N-dialkyl-aminomethyl)pyrrolidines and (S)-methoxymethylpyrrolidine

A convenient synthesis of chiral lithium N-alkyl carbamates 1a–4a from chiral pyrrolidines 1–4, LiH and CO₂ is described. The yields are good to excellent. A combined experimental (¹H, ⁶Li-HOESY, cryoscopy) and theoretical study (B3LYP/6-311++G(d,p)) succeeded in assigning the predominant solution state structure of 1a.