Ap Jekel

SYNTHESES AND STRUCTURES OF PRECURSORS IN THE POLYCONDENSATION OF HEXACHLOROCYCLOTRIPHOSPHAZENE AND HYDROQUINONE

Abstract Under controlled reaction conditions and without using a phase-transfer catalyst the polycondensation of (NPCl2)3 and hydroquinone leads to a mixture of oligomers with formula N3P3Cl5[(p-OC6H4O)N3P3Cl4]n(pOC6H4O)N3P3Cl5. The first compound (n=O) in this series could be isolated in a pure state. In addition very small quantities of double-bridged species N3P3Cl4(p-OC6H4O)2N3P3Cl4 have been detected. At 130 K crystals of N3P3Cl5(pOC6H4O)N3P3Cl5 are triclinic, space group P 1 , a=7.979(4), b=12.041(6), c=13.883(4) A, α=64.87(4), β=81.28(3), γ=87.48(4)°, Z=2. The refinement converged to RF=0.031 for 4203 reflections with F⩾ 4.0 σ(F). In the molecules the NP rings are in trans position with respect to the organic part. The presence of the catalyst Bu4NBr accelerates the polymerization reaction. From the reaction mixture one of the two double-bridged isomers could be isolated in a pure state. The reaction pathway during the polymerization is discussed as well as the structure of the resulting polymers.

Cytostatic activity of inorganic heterocycles in an in vitro screening system.

Six representatives of inorganic cyclic systems (NPAz2)2 NSOX(Az = aziridino, X = F, Az, Ph) and (NPAz2)2 NPAzR [R = Az, Morph (morpholino), Pyr (pyrrolidino)] show cytostatic activity in an in vitro screening system. The technique of the in vitro screening system used is described. L5178Y and Ehrlich ascites cells are grown as suspension cultures in concave-bottomed wells in microtiter test plates using serial dilutions of the drugs in the medium. The diameter of the cell sedimentation spots, which can be compared visually is taken to determine the lowest active dose. The results of this test correspond with the cytostatic activities observed in former in vivo experiments.

Thermal behavior of novel hybrid inorganic-organic phosphazene polymers

The thermal behavior of the following systems have been investigated by TGA and XPS: the homopolymer of N:P:Cl4(CH2)(CH2C6H4CH−CH2) (1). copolymers of1 with MMA and styrene, and copolymers of N:P:Cl4(1-C3II) [C[OC(O)CH3]−CH3] (2) with MMA and styrene. Upon heating under TGA conditions the highest char yield (64wt00) is found for the homopolymer of1. The char yields for the copolymers appear to increase with increasing amounts of phosphazene incorporated. The one-step weight loss observed for the homopolymer of1 can be ascribed mainly to climination of HCl. The1 styrene copolymers decompose in one step, indicating that HCl elimination, ring degradation, and depolymerization take place simultaneously. The1 MMA copolymers show a two-step degradation. From XPS scans it follows that complete loss of chlorine takes place in the first step and probably in combination with some depolymerization of MMA units. In the second step phosphazene ring degradation is observed, accompanied by further carbonization of the sample. The2 styrene copolymers start to decompose about 100 C lowe than the1 MMA copolymers, also exhibiting a two-step TGA curve. The first step can be associated with breakdown of polymer chains at the C−C linkage between inorganic monomers. In the second step depolymerization of the styrene sequences. HCl elimination, and ring degradation occur.

Preparation and polymerization of styrene, acrylate and methacrylate substituted cyclophosphazenes

Abstract Radical polymerization and copolymerization reactions involving olefin substituted cyclophosphazenes lead to hybrid inorganic-organic polymers and copolymers, which are characterized by a carbon-carbon backbone and pendant phosphazenic groups. The stability of the polymers prepared is related to their structures. The thermal behaviour of poly(cyclophosphazenemethacrylate) (PCPhMA), which appears to possess flame-retardant properties, is compared with that of poly(methylmethacrylate) (PMMA).

Polymerization of an acetoxyvinyl substituted chlorocyclophosphazene

The vinyl acetate derivative, gem-isopropyl-2-(α-acetoxyvinyl)tetrachlorocyclotriphosphazene (1), has been used in radical homopolymerization and copolymerization reactions with methyl methacrylate, (MMA) and styrene. The 1,1-disubstituted olefin did not undergo radical homopolymerization. Copolymers derived from MMA and 1 contained only low amounts (<2 mol%) of 1. A maximum incorporation of 20 mol% of phosphazene monomer was achieved with styrene as comonomer. The data obtained in low- and high-conversion copolymerizations with styrene were used to calculate the monomer reactivity ratios. The results of the calculations show that the terminal model is not operative. Calculation for the penultimate model with r2=0 resulted in r1 and r′1 values of 2.8±0.2 and 0.7±0.1, respectively. For the hypothetical homopolymer of 1 a Tg value of 441 K was calculated. All the copolymers with styrene exhibit flame-retardant properties.

NOVEL PHOSPHAZENE-SUBSTITUTED SILOXANES AND SILANES

Abstract Cyclophosphazene-substituted siloxanes and silanes are prepared by the method of hydrosilylation, starting from allylderivatized cyclophosphazenes and hydrosiloxanes or hydrosilanes in the presence of a platinum catalyst. Steric and electronic effects govern the course of the reaction.

Structure of the tetrabutylammonium salt of 2,4,4,6,6-pentachloro-1,3,5,2λ5,4λ5,6λ5-triazatriphosphorinine 2-oxide

[N(C4H9)4][N3P3C150], Mr--- 570.67, monoclinic, P2Jc, a=10.184(2), b=18.072(3), c = 16.448 (2) A, fl = 106.88 (2) °, V= 2896-8 (9) A 3, Z = 4, Dx = 1.308 g cm -3, A(Mo K~) = 0-71073 A, /z = 6-8 cm-i, F(000) = 1192, T = 298 K, RF = 0.082, wR = 0.069 for 2089 unique observed reflections with I >_ 1.5tr(/) and 263 parameters. The inorganic ring skeleton is nearly flat, tending somewhat to a crown conformation. The P--N bond lengths (mean values) are: N--P(OC1) 1.606 (5) A and N--P(C12) 1.540 (5), 1.58 (1) A.

New designs and structure activity relationships in antitumoral aziridinyl cyclophospha(thia)zenes

Abstract The partial aziridinolysis of (NPCl2)3,4 and (NPCl2)2 NSOCl yields non-geminal and geminal chloro-aziridinyl derivatives. Compounds N3P3Az6-nRn (R[dbnd]amino, alkoxy, aryloxy, id.) show in vitro and in vivo cytostatic activity. Structure-activity relationships are proposed. Phase I clinical trials of (NPAz2)2 NSOAz (Az[dbnd]1-aziridinyl) are summarized.

Inorganic ring systems of physiological importance. Part II+. Substituent effects in the aziridinolysis of (NPCl2)3

Abstract The aziridinolysis of (NPCl2)n(NPAmCl)3−n(n = 1, 2; Am = pyrrolidino, piperidino, morpholino) in diethyl ether is described. In a series of comparable reactions it is found that the replacement of chlorine atoms takes place at PCl2 rather than at PAmCl centres. Thus, the presence of the secondary amino ligands causes a retardation of the aminolysis of the PAmCl centres by the weak mucleophile aziridine (ethylene imine, NH(CH2)2). Concerning the reactivity of the PAmCl centres the following sequence is observed:* PPyrCl > PPipCl > PMorphCl Apart from steric effects this sequence can be related to differences in the electron-donating ability of the amino groups, giving rise to changes in the leaving group capacity of the chlorine atoms. Moreover, the reactivity of the PAmCl centres in NPCl2(NPAmCl)2 is related to the mutual position of the amino substituents.

Novel alkenyl substituted cyclophosphazenes for the synthesis of thermally stable polymers

ABSTRACT. The synthesis of some new alkenyl substituted tetrachlorocyclophosphazenes is discussed. The reaction of acetyl chloride with a hydridocyclophosphazene yielded a vinylacetate derivative or a carbon-bridged bicyclophosphazene. Elimination reactions with (NPCl2)2NP(iPr)C(CH3)2OSO2CH3 yielded a propene derivative and an ANSA compound. X-ray structures of the bicyclophosphazene and ANSA compound are presented. The vinylacetate and propene derivatives did not homopolymerize under radical conditions. Copolymerization with styrene resulted in polymers with a maximum incorporation of 17 mol% for the vinylacetate derivative and 18 mol% for the propene derivative. In TGA studies high char yields up to 64 wt% were observed for the homo- and copolymers of the vinylbenzyl substituted tetrachlorocyclophosphazene. XPS studies showed the residue to contain P, N and C.