Some reactions of 1,3,5-Triaza-7-phosphaadamantane and its 7-Oxide

The synthesis of 1,3,5,7-triazaphosphocine and 1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane derivatives via nitration, nitrosation and acetylation of 1,3,5-triaza-7-phosphaadamantane and its 7-oxide is reported. A comparison of the reactions of the triazaphosphaadamantane with the analogous reactions of hexamine is made.     

Mechanochemical P-derivatization of 1,3,5-Triaza-7-Phosphaadamantane (PTA) and Silver-Based Coordination Polymers Obtained from the Resulting Phosphabetaines

We have described earlier that in aqueous solutions, the reaction of 1,3,5-triaza-7-phosphaadamantane (PTA) with maleic acid yielded a phosphonium-alkanoate zwitterion. The same reaction with 2-methylmaleic acid (citraconic acid) proceeded much slower. It is reported here, that in the case of glutaconic and itaconic acids (constitutional isomers of citraconic acid), formation of the corresponding phosphabetaines requires significantly shorter reaction times. The new phosphabetaines were isolated and characterized by elemental analysis, multinuclear NMR spectroscopy and ESI-MS spectrometry. Furthermore, their molecular structures in the solid state were determined by single crystal X-ray diffraction (SC-XRD). Synthesis of the phosphabetaines from PTA and unsaturated dicarboxylic acids was also carried out mechanochemically with the use of a planetary ball mill, and the characteristics of the syntheses in solvent and under solvent-free conditions were compared. In aqueous solutions, the reaction of the new phosphabetaines with Ag(CF₃SO₃) yielded Ag(I)-based coordination polymers. According to the SC-XRD results, in these polymers the Ag(I)-ion coordinates to the N and O donor atoms of the ligands; however, Ag(I)-Ag(I) interactions were also identified. The Ag(I)-based coordination polymer (CP1.2) formed with the glutaconyl derivative of PTA (1) showed considerable antimicrobial activity against both Gram-negative and Gram-positive bacteria and yeast strains     

Development of a series of P(CH(2)N=CHR)(3) and trisubstituted 1,3,5-Triaza-7-phosphaadamantane ligands

The synthesis and structure of a series of novel phosphine ligands derived from the condensation of P(CH2NH2) with aldehydes are described. Depending on the reaction conditions, either substituted tris(iminomethyl)phosphine, P(CH2N=CHR)3, or 1,3,5-triaza-7-phosphaadamantane structures substituted at the "lower rim", PTAR3, are obtained.     

1,3,5-Triaza-7-Phosphaadamantane (PTA) as a 31P NMR Probe for Organometallic Transition Metal Complexes in Solution

Due to the rigid structure of 1,3,5-triaza-7-phosphaadamantane (PTA), its ³¹P chemical shift solely depends on non-covalent interactions in which the molecule is involved. The maximum range of change caused by the most common of these, hydrogen bonding, is only 6 ppm, because the active site is one of the PTA nitrogen atoms. In contrast, when the PTA phosphorus atom is coordinated to a metal, the range of change exceeds 100 ppm. This feature can be used to support or reject specific structural models of organometallic transition metal complexes in solution by comparing the experimental and Density Functional Theory (DFT) calculated values of this ³¹P chemical shift. This approach has been tested on a variety of the metals of groups 8–12 and molecular structures. General recommendations for appropriate basis sets are reported.     

Syntheses and Structural Characterization of Tetrahedral Four-Coordinate Gold(I) Complexes of 1,3,5-Triaza-7-phosphaadamantane. An Example of a Hydrogen-Bond-Directed Supramolecular Assembly

The synthesis and structural characterization of water-soluble four-coordinate gold(I) complexes containing monodentate phosphine ligands are described. The ligands used are 1,3,5-triaza-7-phosphaadamantane (TPA) and its protonated and methylated derivatives, [HTPA]Cl and [MeTPA]I. Formation of the four-coordinate gold(I) species is favored by the small cone angle of the phosphine (102 degrees ) and its ability to form a hydrogen-bonded network between the nitrogen atoms of the ligand and solvent water molecules. The gold center in all four complexes has a nearly regular tetrahedral geometry with an average P-Au-P angle of 109.5 degrees. [(HTPA)(3)(TPA)Au](PF(6))(4).4H(2)O.CH(3)CN(1) crystallizes in the monoclinic space group P2(1)/c (No. 14) with cell constants a = 20.719(3) ?, b = 15.606(2) ?, c = 17.854(2) ?, beta = 114.03(1) degrees, and Z = 4. Refinement of 4977 reflections and 650 parameters yields R = 0.0396 and R(w) = 0.0500. [(TPA)(4)Au]PF(6).1.5HCl.H(2)O (2), crystallizes in the monoclinic space group C2/c (No. 15) with cell constants a = 33.036(7) ?, b = 11.212(2) ?, c = 31.503(5) ?, b = 137.58(1) degrees, and Z = 8. Refinement of 3835 reflections and 470 parameters yields R = 0.0351 and R(w) = 0.0403. [(TPA)(4)Au]Cl(4).6H(2)O (3) was characterized structurally in the cubic space group Fd&thremacr;m (No. 227) with cell constants a = b = c = 20.020(2) ? and Z = 8. Refinement of 290 reflections and 28 parameters yields R = 0.0624 and R(w) = 0.1291. [(MeTPA)(4)Au](PF(6))(5).2CH(3)CN (4) crystallizes in the monoclinic space group C2/c (No. 15) with cell constants a = 23.337(3) ?, b = 14.855(3) ?, c = 35.317(5) ?, b = 97.95(1) degrees, and Z = 8. Refinement of 7840 reflections and 621 parameters yields R = 0.0493 and R(w) = 0.0698.     

1,3,5-Triaryl-Δ2-pyrazoline

2-Iodo-3-chloro-1,3-diphenyl-1-propanones react with phenylhydrazine to yield the 1,3,5-Triaryl-Δ²-pyrazoline. The reaction proceeds with elimination of ICl to the chalcones and their reaction with an excess of phenylhydrazine.     

1,3,5-trisubstituted 1,4-diazepin-2-ones

Six 1,3,5-trisubstituted 1,4-diazepin-2-ones were synthesized by a sequence featuring the cascade addition of vinyl Grignard to N-[Boc-aminoacyl]-N-alkyl-beta-amino esters, followed by Boc group removal and annulation by a reductive amination. Relative to the parent sequence employing N-Boc-aminoacyl beta-amino esters to make 3,5-disubstituted heterocycle, the additional N-alkyl substituent caused a noticeable acceleration and gave relatively higher yield in the 1,4-diazepin-2-one annulation.     

Synthesis of 1,3,5-tris(2-chloroethyl)- and 1,3,5-tris(2-iodoethyl)benzenes

A new method has been elaborated for the synthesis of 1,3,5-tris(2-chloroethyl)- and 1,3,5-tris(2-iodoethyl)benzenes based on the commercially available 1,3,5-tribromobenzene.     

Heterocycles from heterocycles. - III[1]. 1,3,5-trisubstituted hexahydro-1,3,5-triazines-2-ones from 1,3,5-trisubstituted hexahydro-1,3,5-triazines and organic isocyanates

1,3,5-Triscubstituted hexahydro-1,3,5-trazin-2-ones 3 are easily obtained by the reaction of 1,3,5-trisub-stituted hexahydro-1,3,5-triazines 1 with organic isocyanates 2 . The reaction is believed to occur by the sequential addition to 2 of two molecules of the monomeric N-methyleneamines in thermal equilibrium with 1. Substituent scrambling at the operating temperature (120°) was negligible. The crystal structure of 1,3,5-triphenylhexahydro-1,3,5-triazin-2-one (3a) has been determined by X-ray diffraction methods.     

5-Substituted 2-alkyl- and 2-arylsulfonyliminohexahydro-1,3,5-triazines

A new procedure was developed for the preparation of previously unknown 5-substituted 2-alkyl- and 2-arylsulfonyliminohexahydro-1,3,5-triazines by cyclocondensation of sulfoguanidines with formaldehyde and primary alkyl(aryl)amines.     

A study of the sensitivity and decomposition of 1,3,5-trinitro-2-oxo-1,3,5-triazacyclo-hexane

The thermal decomposition and thermal stability of 1,3,5-trinitro-2-oxo-1,3,5-triazacyclohexane (keto-RDX or K-6) was studied. The keto-RDX synthesis is described, mass spectra (electron impact (70 eV) and chemical ionization) similar to RDX spectra registered under identical conditions are presented, and mass spectroscopy fragmentation paths are proposed. The LI-MS (laser induced/mass spectroscopic) results imply that the first step in the decomposition of keto-RDX is the elimination of NO₂ or HONO and subsequent breakdown of the triazacyclohexane ring. The thermal stability, activation energy (E_a = 140 kJ mol⁻¹), and frequency factor (K₀ = 9 × 10⁹ s⁻¹) in the temperature interval 90-120°C were measured using chemiluminescence (NO detection only). The activation energy was also determined from DSC data using the ASTM method E 698-79, and was found to be 280 kJ mol⁻¹ with a frequency factor of 7.0 × 10²⁹ s⁻¹ in the temperature interval 175-200°C. Microcalorimetry, drop-weight test, friction test, and ignition temperature (Wood's metal bath) measurements were also conducted. Quantum mechanical calculations (semi-empirical method with PM3 set at the unrestricted Hartree-Fock level) were conducted to correlate the sensitivity and thermal decomposition with those of RDX. No significant differences in bond-breaking energies for RDX and keto-RDX were found. Conclusions drawn from the experiments are that the decomposition of keto-RDX is auto-catalytic, and that the sensitivity of keto-RDX is not connected with the initial bond-breaking step. More than one method for measuring the risk involved in handling an explosive is necessary since the sensitivity depends on different stages in the decomposition.     

Reactions of 1,3,5-triazinylnitro-formaldoximes. 2*. The reaction of 1,3,5-triazinylnitroformaldoximes with monosubstituted acetylenes

1,3,5-Triazinylnitrile oxides were prepared in situ from 2-R-4-R′-1,3,5-triazin-6-ylnitroformaldoximes and were treated with substituted acetylenes to give 3,5-disubstituted isoxazoles. The X-ray data obtained for 5-hydroxymethyl-3-(4′-dimethylamino-2′-methoxy-1,3,5-triazin-6′-yl)isoxazole is discussed.