Organic phosphorus compounds : LXXI. Preparation,properties, and structure of bis(aminomethyl)phosphinic acid, (H2NCH2)2P(O)OH

Bis(aminomethyl)phosphinic acid, (H₂NCH₂)₂P(O)OH · HCl, was prepared by debenzylation of (C₆H₅CH₂NHCH₂)₂P(O)OH · HCl with hydrogen using 5% Pd on C as catalyst, and from bis(t-butylaminomethyl)phosphinic acid, (t-C₄H₉NHCH₂)₂P(O)OH, by isobutylene elimination in concentrated aqueous hydrobromic acid at 175°C in sealed tube. Interaction of bis(chloromethyl)phosphinic acid with ammonia in an autoclave produced methylaminomethylphosphinic acid, CH₃NHCH₂P(O)(OH)₂. A mechanism for the formation of this product is proposed. Several derivatives of (H₂NCH₂)P(O)OH such as (RNHCH₂)₂P(O)OH, R = C₆H₅CO, CICH₂CO, [H₂NHNC(=NH)NHCH₂]₂P(O)OH and [(CH₃)₃SiNHCH₂]₂P(O)OSi(CH₃)₃ were prepared.     

Disproportionation of manganese(II) (1-hydroxyethylidene) diphosphonate in reaction with 2-aminoethanol

Reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate Mn(H₃L)₂ · 4H₂O with 2-aminoethanol H₂NCH₂CH₂OH in an aqueous solution on heating to 70–80°C causes the initial formation of soluble tris(2-hydroxyethanaminium) manganese(II) bis(1-hydroxyethylidene) diphosphonate Mn(H₃L)₂ · 3H₂NCH₂CH₂OH · 4H₂O, which next disproportionates into poorly soluble 2-hydroxyethanaminium manganese(II) (1-hydroxyethylidene)diphosphonate MnH₂L · H₂NCH₂CH₂OH and metal-cation-free coordination polymer of (1-hydroxyethylidene)diphosphonic acid with 2-aminoethanol. Poorly soluble MnH₂L · H₂NCH₂CH₂OH can be readily converted into the soluble form by treatment with 2-aminoethanol or 2-amino-2-(hydroxymethyl)propane-1,3-diol H₂NC(CH₂OH)₃.     

C,N‐chelated triorganotin(IV) diesters of 4‐ketopimelic acid and their fungicidal activity

The set of four triorganotin(IV) diesters of 4‐ketopimelic acid containing {2‐[(CH₃)₂NCH₂]C₆H₄}‐ as a C,N‐chelating ligand was prepared. Their structures were studied by the help of IR, NMR and X‐ray crystallographic techniques in the case of {{2‐[(CH₃)₂NCH₂]C₆H₄}SnPh₂}₂[(OOCCH₂CH₂)₂C?]. All these compounds are monomeric both in solid state and solution with five‐coordinated tin atoms and medium strong intramolecular Sn? N connection. The antimycotical activity of these compound was studied and compared with the triorganotin(IV) derivatives of 4‐ketopimelic acid and antimycotical drugs in clinical use. Copyright © 2008 John Wiley & Sons, Ltd.     

Water-soluble cobalt complexes with 1-hydroxyethylydenediphosphonic acid and 2-aminoethanol

The reaction of an aqueous suspension of basic cobalt carbonate CoCO₃·4Co(OH)₂·3H₂O with equimolar amount or two-fold excess of 1-hydroxyethylydenediphosphonic acid (H₄L) has yielded crystalline CoH₂L and amorphous Co(H₃L)₂ products, respectively. The interaction of poorly soluble CoH₂L complex with 2-aminoethanol has resulted in the formation of amorphous water-soluble CoH₂L·H₂NCH₂CH₂OH·6Н₂О complex; the latter loses 5 water molecules at heating and is converted into CoH₂L·H₂NCH₂CH₂OH·Н₂О. The study of agrochemical effects of Co(H₃L)₂ and CoH₂L·H₂NCH₂CH₂OH·6Н₂О has revealed their advantage over the conventional salt form (cobalt sulfate) reflected in the reduced phytotoxicity of the element. The prepared compound containing 2-aminoethanol (solubility promotor) has revealed better performance.     

Schiff base derivatives of lanthanons,La(III), Pr(III), Nd(III) and Sm(III) complexes of bifunctional tetradentateSchiff base

Reactions of La(III), Pr(III), Nd(III) or Sm(III) nitrate with bifunctional tetradentateSchiff base, [o-HOC₆H₄C(CH₃): :NCH₂]₂, having the donor system HO–N–N–OH in 12 molar ratio have been investigated and found to yield new derivatives of the type [Ln(SBH₂)₂](NO₃)₃ [whereLn=La(III), Pr(III), Nd(III) or Sm(III) andSBH₂=Schiff base molecule, [o-HOC₆H₄C(CH₃) : NCH₂]₂. On the basis of elemental analyses, conductivity and magnetic measurements and infrared spectra, plausible structures for the resulting complexes have been indicated.     

Author Index to Volume 62

The gaseous reaction of oxygen atoms with dimethylamine was studied in a cross-jet reactor and found to proceed by electrophilic addition to form an energy-rich N-oxide which rearranges to an hydroxylamine and then decomposes via three routes: (CH₃)₂ N + OH, CH₃NCH₂ + H₂O and CH₃NHO + CH₃.     

Syntheses,characterization and crystal structures of two square-planar Ni(II) complexes with unsymmetrical tridentate Schiff base ligands and monodentate pseudohalides

Two new square-planar Ni(II) complexes, [NiL¹(NCS)] (1) and [NiL²(N₃)] (2) have been synthesized with the unsymmetrical tridentate Schiff base ligands [(CH₃)₂NCH₂CH₂N=C(CH₃)CH=C(OH)(C₆H₅)], L ¹ H, derived from benzoylacetone and 2-dimethylaminoethylamine and [(CH₃CH₂)₂NCH₂CH₂N=C(CH₃)CH=C(OH)(C₆H₅)], L ² H, derived from benzoylacetone and 2-diethylaminoethylamine, respectively. The complexes have been characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, electrochemical and thermal methods (where applicable). Structures have been established by the single-crystal X-ray diffraction technique which reveals the discrete nature of the complexes in which the metal centers adopt a distorted square planar geometry. Coordination environments of the metal ions in the complexes are satisfied with two different unsymmetrical Schiff base ligands having similar N₂O donor sets and a terminal pseudohalide anion (thiocyanate for 1 and azide for 2).     

Schiff base derivatives of lanthanons

Bifunctional tridentate Schiff bases such as, $$\begin{gathered} HOC_6 H_4 C(CH_3 ) : NCH_2 CH_2 OH, \hfill \\ HOC_6 H_4 C(CH_3 ) : NCH_2 CH_2 (OH)CH_3 , \hfill \\ HOC_6 H_4 C(H) : NCH_2 CH_2 OH \hfill \\ \end{gathered} $$ and HOC₆H₄C(H)∶NCH₂CH(OH)CH₃ react with La(III), Pr(III) and Nd(III) isopropoxides to 1∶1 and 2∶3 derivatives of the type,Ln(O?i-C₃H₇)(OC₆H₄C[R]∶NR′O) andLn ₂(OC₆H₄C[R]∶ NR′O)₃ [where,Ln=La(III), Pr(III) or Nd(III); R=CH₃ or H and R′=CH₂?CH₂ or CH₂CHCH₃] in dry benzene. The labile nature of the isopropoxy groups in the 1∶1 derivatives has been shown by exchange reactions with an excess oft-butyl alcohol leading to the formation ofLn(O?t-C₄H₉)(OC₆H₄C[R]∶NR′O); (where R=CH₃ and R′=CH₂CHCH₃) type derivatives in almost quantitative yield. The IR spectra of the resulting derivatives have been recorded in the range of 4000–400 cm^?1, ν C=N frequency bands appear at ≈ 1620 cm^?1 and almost no change has been noted in their positions on complexation. Some new peaks are, however, observed in the range of 700–600 cm^?1 and these may be ascribed to the ring deformation coupled with both theLn?O stretching and C?CH₃ stretching modes.     

Hydrate and Alcoholate Forms of Phosphomolybdic Heteropolyacid and Their Formation under Conditions of Isothermal Sorption of Water,Methanol, and Ethanol Vapors

Reaction of water, methanol, and ethanol vapors with a solid phosphomolybdic acid at room temperature is accompanied by formation of bulk hydrates and alcoholates. The reaction involves several stages which are readily detected by the sorption and desorption isotherms. The formation of alcoholates causes loosening of the acid lattice, thus favoring much more active initial sorption of alcohols, compared with water, and liquefaction once H₃PMo₁₂O₄₀·11.5CH₃OH and H₃PMo₁₂O₄₀·14.7C₂H₅OH compositions are attained.     

Organoselenium compounds containing pyrazole or phenylthiazole groups: Synthesis,structure, tin(IV) complexes and antiproliferative activity

The diorganodiselenides (pzCH₂CH₂)₂Se₂ ( 1 ) and (PhtzCH₂)₂Se₂ ( 2 ) were prepared by reacting Na₂Se₂ with 1‐(2‐bromoethyl)‐1H‐pyrazole and 4‐(chloromethyl)‐2‐phenylthiazole, respectively, while the reactions between 1‐(2‐bromoethyl)‐1H‐pyrazole or 4‐(chloromethyl)‐2‐phenylthiazole and the lithium organoselenolates [2‐(Et₂NCH₂)C₆H₄]SeLi and [2‐{O(CH₂CH₂)₂NCH₂}C₆H₄]SeLi in a 1:1 molar ratio resulted in the heteroleptic diorganoselenium(II) compounds [2‐(Et₂NCH₂)C₆H₄](R)Se (R = pzCH₂CH₂ ( 3 ) or PhtzCH₂ ( 5 )) and [2‐{O(CH₂CH₂)₂NCH₂}C₆H₄](R)Se (R = pzCH₂CH₂ ( 4 ) or PhtzCH₂ ( 6 )). The diorganotin(IV) bis(organoselenolato) derivatives of type R₂Sn(SeCH₂CH₂pz)₂ (R = 2‐(Me₂NCH₂)C₆H₄ ( 7 ) or Me ( 8 )) were obtained by reacting (pzCH₂CH₂)SeNa with the appropriate diorganotin(IV)dichloride in a 2:1 molar ratio. All compounds were investigated using NMR spectroscopy (¹H, ¹³C, ⁷⁷Se, ¹¹⁹Sn as appropriate) and ESI+ mass spectrometry. The molecular structures of 2 and 6 were determined using single‐crystal X‐ray diffraction. The formation of a 10–Se–3 hypercoordinated species was evidenced for 6 in the solid state, as a consequence of the C,N coordination behaviour of the 2‐{O(CH₂CH₂)₂NCH₂}C₆H₄ group. Compounds 1 , 7 and 8 were investigated for their antiproliferative activity towards the mouse colon carcinoma C26 cell line with the preliminary results showing a better activity than 5‐fluorouracil.     

Identification of an OH,CH combination band in the near infrared spectrum of ethanol

The identification of an OH_stretch/CH_stretch combination band in the near infrared (n.i.r.) spectrum of ethanol is based on comparison of the calculated positions of overtone and combination bands with the n.i.r. spectra of C₂H₅OH, C₂H₅OD, CH₃OH and CH₃OD.     

Formation,Characterization, and Stability of Novel Aluminocarbosilazane Macromolecules

Abstract

A novel class of polycarbosilazane?AlCl₃ macromolecules (AlCSZ) with a Si/Al molar ratio of 1 : 1, 2 : 1, and 3 : 1 were prepared by a two‐step reaction, formation of H₂NCH₂CH₂NH₂?AlCl₃ adducts followed by condensation of H₂NCH₂CH₂NH₂ with (CH₃)₂SiCl₂ in an aprotic solvent containing triethylamine base. The resulting AlCSZ materials were examined by elemental analysis, infrared spectroscopy (FT‐IR), mass spectrometry (MS), and powder x‐ray diffraction (XRD). The average polycarbosilazane chain–chain distances in the aluminum‐free polycarbosilazane and these AlCSZ macromolecules were estimated from the XRD data and found to be 5.94, 6.75, 6.88, and 7.19 Å, respectively. This demonstrates that AlCl₃ is incorporated between the polycarbosilzane chains and has caused chain–chain expansion. The thermal properties of these AlCSZs were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). They are air stable white solids but decompose in water forming the corresponding dimethylsiloxane, ethylenediamine, and aluminum oxide.     

Hydrothermal Synthesis,Crystal Structure,and Thermal Stability of Two New Metal Phosphonates with a Pillared Layered Structure

Two new metal phosphonates with a 3D pillared layered framework based on N,N′‐piperazinebis(methylenephosphonic acid), H₂O₃PCH₂NC₄H₈NCH₂PO₃H₂ (H₄L), Sn[O₃PCH₂NHC₄H₈NHCH₂PO₃] ( 1 ) and Pb₃(OH)₂[O₃PCH₂NC₄H₈NCH₂PO₃] ( 2 ), have been synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1 , each ψ‐square pyramidal SnO₄ unit is in turn corner‐shared by four CPO₃ tetrahedral from four different phosphonate ligands to form two‐dimensional inorganic puckered layers in ab planes. In compound 2 , the complicated inorganic layer (bc planes) is built up of ψ‐PbO₄N, PbO₆ and CPO₃ polyhedra. The overall structure for two compounds may be described in terms of alternating inorganic infinite layers and organic pillars {CH₂N(C₂H₄)₂NCH₂}, to form a 3D pillared layered structure.     

Kinetics of hydrolysis of amino acid esters in presence of aquocomplexes involving ethylenediamine,diethylenetriamine and triethylenetetramine ligands. Part 1-copper(II) and nickel(II)

Summary Aquocomplexes of copper(II) and nickel(II) involving (H₂NCH₂)₂, H₂NCH₂CH₂NHCH₂CH₂NH₂ and H₂NCH₂CH₂NHCH₂CH₂NHCH₂CH₂NH₂ as ligands were prepared and characterised. Using a pH-stat method, the kinetics of the base hydrolysis of amino acid esters such as H₂NCH₂CO₂CH₃·HCl (GE), (HO)C₆H₄CH₂-(NH₂)CO₂CH₃·HCl (TE), CH₃S(CH₂)₂CH(NH₂)CO₂CH₃· HCl (ME), HSCH₂CH(NH₂)CO₂C₂H₅·HCl (CE), (HE) and [—SCH₂CH(NH₂)CO₂CH₃]₂·2HCl (CysE) was studied. These complexes substantially enhance the rate of hydrolysis, the values of the second-order rate constants being some 10–30 times greater than those obtained in the presence of simple metal ions.     

Structure of C, N-chelated nButyltin(IV) fluorides and their use as fluorinating agents of some chlorosilanes, chlorophosphine and metal halides

The tin atom in the solid-state structure of {2-[(CH₃)₂NCH₂]C₆H₄}nBu₂SnF is five coordinated with carbon atoms in equatorial and fluorine and nitrogen atoms in axial positions. The fluorination of {2-[(CH₃)₂NCH₂]C₆H₄}nBuSnCl₂ is described by NMR methods. The successful attempts to fluorinate various chlorosilanes, chlorophosphine and metal halides are also reported.     

A green synthesis of nitrones from diamino glyoxime using aldehydes and ketones

The reaction of diaminoglyoxime with aldehyde and ketone derivatives in the presence of p-toluene sulphonic acid in H₂O–MeOH mixture at room temperature afforded nitrone derivatives in high yields within 10–140 min. The applicability of ketones in this reaction for the preparation of novel nitrones has been verified. The effect of the temperature on the stability of the structural isomers of the products has been studied by NMR as well. The results showed that, at high temperatures only one product could be observed. The nature of solvent and catalyst were evaluated and found that the strong acids H₂SO₄ and CF₃SO₃H in protic solvent CH₃OH work well while neither CH₃SO₃H in protic solvent nor p-toluene sulphonic acid in aprotic solvents toluene and THF perform the same reactions.     

Physico-chemical properties of N,N-di(2-hydroxyethyl)alkylamines

In view of potential application of N-alkyl derivatives of diethanolamine RN(CH₂CH₂OH)₂ (R = C₈H₁₇, C₁₀H₂₁, C₁₂H₂₅, and C₁₄H₂₉) as surfactants, we have studied their physico-chemical properties, constructed the surface tension isotherms at the liquid-gas interphase boundary in the cases of water and aqueous hydrochloric acid, and estimated critical micelle concentrations as well as surface activity of the studied compounds.     

Facile syntheses, structural characterizations, and isomerization of disiloxane-1,3-diols

In the hydrolysis reaction of dichlorosilanes having an intramolecular coordinating atom, dcisiloxane-1,3-diols, [(OH){o-(CH₃)₂NCH₂-C₆H₄}RSi]₂O(R=CH₂CH (1), C₆H₅ (2), o-(CH₃)₂NCH₂C₆H₄ (3), Me (4)), were obtained in high yields. The results of the crystal structure analyses of meso-2, rac-2a, rac-2b and 3 are reported. They showed strong intramolecular hydrogen bondings between the hydroxy group and the nitrogen atom. We have also found that the diastereomeric isomerization of meso-2 to rac-2 in CDCl₃ solvent containing moisture occurred to result in the 55:45 equilibrium mixtures of the isomers and vice versa.     

Investigations on the Synthesis,Structural Characterization,and Crystal Structures of Three Diiron and Tetrairon Azadithiolate Complexes

Three diiron and tetrairon azadithiolate complexes as models for the active site of [FeFe] hydrogenase were prepared. Reaction of complex Fe₂(SCH₂OH)₂(CO)₆ and NH₂CH₂CH₂CH₂OCH₃ resulted in the diiron azadithiolate hexcarbonyl complex Fe₂[(SCH₂)₂NCH₂CH₂CH₂OCH₃](CO)₆ ( 1 ) in moderate yield. Furthermore, treatment of complex 1 with mono phosphine ligand PPh₃ and diphosphine ligand Ph₂PCH₂CH₂PPh₂ in the presence of decarbonylation reagent Me₃NO · 2H₂O yielded the phosphine‐substituted azadithiolate complexes Fe₂[(SCH₂)₂NCH₂CH₂CH₂OCH₃]CO)₅(PPh₃) ( 2 ) and {Fe₂[(SCH₂)₂NCH₂CH₂CH₂OCH₃](CO)₅}₂(Ph₂PCH₂CH₂PPh₂) ( 3 ) respectively. The new complexes 1 – 3 were fully characterized by elemental analysis, IR, ¹H, ¹³C, ³¹P NMR spectroscopy and X‐ray crystallography. It is worthy to note that the crystallographic studies show the unusual difference of the methoxypropanyl substituent on the N atom of complexes 1 and 2 , largely because of the affection of phosphine ligand PPh₃. In addition, complex 1 was found to be a catalyst for H₂ production under electrochemical condition.     

Laser isotope separation and the multiphoton decomposition of methanol using a pulsed HF or DF laser

The focussed beam from a single line [P₁(6)] pulsed HF laser has been used to decompose CH₃OH (for pressures between 0.169 and 14.95 kPa) and isotopic mixtures of methanol. The normalized yields (number of product molecules Pulse/P_METHANOL) of the non-condensable products H₂, CO and CH₄ increased linearly with pressure (for the range ≈ 1 - 7 kPa). For sufficiently low pressures, selective excitation of one component of an isotopic mixture gives an isotopically enriched product. For example, selective excitation of CH₃OH in equimolar of mixture CH₃OH/CH₃OD at a total pressure of 269 Pa gives hydrogen which is enriched 60-fold in H versus D. The degree of isotopic enrichment decreases with increasing mixture pressure. The efficiency of conversion of photon energy to reaction product has been observed to increase linearly with pressure. Decomposition studies have been performed in the presence of additives. These imply that the decomposition of methanol to H₂ involves mainly molecular rather than free radical steps.