Gabino A. Carriedo

On the synthesis of functionalized cyclic and polymeric aryloxyphosphazenes from phenols

A very convenient synthetic method is described for the known cyclic aryloxyphosphazenes [N3P3(OC6H4-R)6] (R = Br, CN, CHO, COCH3, COC6H5, and NO2). The method is based on the direct reaction of [N3P3Cl6] with six equivalents of the para-substituted phenols HOC6H4-R and K2CO3 in refluxing acetone and is characterized by very short reaction times and very simple workups, leading directly to the analytically and spectroscopically pure products in very high yields. In the cases where R = H, But, or OCH3, the reactions were much slower, but the time could be shortened by using [Bu4N]Br as the phase-transfer catalyst. Similarly, the polymers [NP(OC6H4-R)2]n can be conveniently obtained in ca. 70% and good analytical purity from polydichlorophosphazene [NPCl2]n and the para-substituted phenols HOC6H5-R (R = Br, CN, COCH3, and NO2) in the presence of K2CO3 using THF as the solvent.

INFRARED AND RAMAN SPECTRA OF THE PHOSPHAZENE HIGH POLYMER NP(O2C12H8)N

The vibrational spectra of a new type of phosphazene polymer, [NP(O2C12H8)]n (polyspirophosphazene), are discussed. The spectra were recorded for powders dispersed in KBr pellets and for films prepared from different solvents. The IR spectra are dominated by the vibrational modes of the main chain whereas the Raman spectra are dominated by the vibrations of the peripheral biphenyl groups. The full width at half maximum (FWHM) of the Raman band at 1609 cm-1, corresponding to one of the CC stretching modes of the biphenyl, decreases with increase in the degree of crystallinity of the polymer sample.

Synthesis, X-ray structure and coordination to Mn(CO)3(bipy)+ of the cyclotriphosphazenes N3P3(OC5H4N-2)6 and N3P3(OC5H4N-4)6

Abstract The hexachlorocyclotriphosphazene [N 3 P 3 Cl 6 ] reacts with 2-hydroxypyridine (HOC 5 H 4 N-2) and 4-hydroxypyridine (HOC 5 H 4 N-4) in acetone in the presence of K 2 CO 3 , to give the hexasubstituted products N 3 P 3 (OC 5 H 4 N-2) 6 ( 1 ) and N 3 P 3 (OC 5 H 4 N-4) 6 ( 2 ). The structure of both compounds has been determined by X-ray diffraction. The hexafunctionalized cyclotriphosphazene N 3 P 3 (OC 5 H 4 N-4) 6 ( 2 ) is a better ligand than 1 and reacts with fac -[Mn(OClO 3 )(CO) 3 (bipy)] in CH 2 Cl 2 to give the hexacationic complex [N 3 P 3 {(OC 5 H 4 N)Mn(CO) 3 (bipy)} 6 ](ClO 4 ) 6 ( 3 ).

Direct synthesis of cyclic and polymeric phosphazenes bearing diphenylphosphine groups and their complexes with [W(CO)5] fragments

Abstract The reactions of the cyclotriphosphazenes [N 3 P 3 Cl 6 ] or [N 3 P 3 (O 2 C 12 H 8 ) 2 Cl 2 ] with the phenolic phosphine PPh 2 (C 6 H 4 -OH) in the presence of Cs 2 CO 3 give, respectively, the cyclic phosphazene phosphines [N 3 P 3 (OC 6 H 4 PPh 2 ) 6 ] ( 1 ) and [N 3 P 3 (O 2 C 12 H 8 ) 2 (OC 6 H 4 PPh 2 ) 2 ] ( 2 ), very pure and in high yield. The similar reaction with the linear polyphosphazene {[NP(O 2 C 12 H 8 )] 0.65 [NPCl 2 ] 0.35 } n in THF gives the diphenylphosphine polymer {[NP(O 2 C 12 H 8 )] 0.65 [NP(OC 6 H 4 PPh 2 ) 2 ] 0.35 } n ( 3 ). The phenolic tungsten pentacarbonyl complex {W(CO) 5 [PPh 2 (C 6 H 4 -OH)]} reacts in the same way with those cyclic and polymeric phosphazenes to give the corresponding complexes {N 3 P 3 [OC 6 H 4 PPh 2 -W(CO) 5 ] 6 } ( 4 ), [N 3 P 3 (O 2 C 12 H 8 ) 2 (OC 6 H 4 PPh 2 -W(CO) 5 ) 2 ] ( 5 ), and {[NP(O 2 C 12 H 8 )] 0.65 [NP(OC 6 H 4 PPh 2 -W(CO) 5 ) 2 ] 0.35 } n ( 6 ).

Synthesis of octahedral carbonyl complexes of manganese (I) with SCN or CN ligands. Crystal structure of fac-[SCNMn(CO)3(dppm)]

Abstract The complexes fac -[XMn(CO) 3 (dppm)], cis , cis -[XMn(CO) 2 (dppm)(P(OPh) 3 )] and trans -[XMn(CO)(dppm) 2 ] with X = SCN or CN have been prepared from the corresponding bromocarbonyls and the salts AgX or KX, or, in the case of the di- and mono-carbonyls, from fac -[XMn(CO) 3 (dppm)] with X = SCN or CN by thermal or photochemical CO substitution by the ligands P(OPh) 3 or dppm. The structure of fac -[SCNMn(CO) 3 (dppm)] has been determined by X-ray diffraction. The crystals are monoclinic, space group P 2 1 / n , and the structure has been refined to R = 0.058 for 4123 reflexions measured in the range 2 ⩽ θ ⩽ 30 at room temperature. The cis , cis -[NCMn(CO) 2 (dppm)(P(OPh) 3 )] complex can be oxidized and subsequently reduced to the isomer trans -[NCMn(CO) 2 (dppm)(P(OPh) 3 )]. All the neutral cyanide complexes react readily with MeI and KPF 6 to give the corresponding methylisocyanide derivatives [Mn(CO) 2 (dppm)(P(OPh) 3 )(CNMe)]PF 6 and [Mn(CO)(dppm) 2 (CNMe)]PF 6 . The stereochemistries of the compounds is discussed in relation to the 31 P NMR spectra.

Molecularly Imprinted Polyphosphazene Films as Recognition Element in a Voltammetric Rifamycin SV Sensor

Molecularly imprinted polyphosphazenes are presented as sensitive coatings for the detection of rifamycin SV in water. These membranes were combined with voltammetric transduction using glassy carbon (GC) working electrodes. The receptor layers were obtained by the drop-coating technique using tetrahydrofuran (THF) solutions containing 0.27 % (m/v) of the polymer and different amounts of template (0.03–0.17 %, m/v). Evaporation of THF results on a water insoluble membrane, which shows good adherence to the GC electrode surface. After removal of the template from the solid polymer membrane, the binding of rifamycin SV was examined by equilibrating the membrane in an aqueous solution of the template. The amount of bound rifamycin SV was measured by cyclic voltammetry or differential pulse voltammetry. Similar experiments were carried out with imprinted membranes using rifampicin as template. Less effective binding was obtained for rifamycin SV in the rifampicin-imprinted polymer. The rifamycin SV sensitive electrode, constructed using the corresponding molecularly imprinted polymer, allows rifamycin SV measurement in the concentration interval between 2.5×10−7 and 6.3×10−6 M.

Synthesis of mono and binuclear carbonyl complexes of manganese with cyanide or thiocyanate ligands. X-ray crystal structure of [{fac-Mn(CO)3(phen)}2(μ-CN)]PF6

Abstract The neutral complexes cis-trans-[MnX(CO)2(bipy)- (P(OPh)3)] (X=I, CN or SCN) have been prepared by nucleophilic substitution of P(OPh)3 by X− in the cationic complex cis-trans-[Mn(CO)2(bipy)- (P(OPh)3)2]+, or, in the case of X=CN, by reacting the iodo-dicarbonyl with AgCN. The cyanide complex reacts with MeI in the presence of KPF6 or with HBF4{dEt2O (of BF3}dEt2O) to give respectively the cationic CNMe or the neutral CNBFF3 derivative. The cyanide species fac-[Mn(CN)(CO)3( N N )] ( N N =bipy or phen) and cis-trans-[Mn(CN)(CO)2(bipy)(P(OPh)3)] react at room temperature with fac- [MnBr(CO)3( N N )] or cis-trans-[MnI(CO)2(bipy) P(OPh)3)] in the presence of TlPF6 to give the corresponding cationic cyanide-bridged complexes [{Mn}aCN{Mn}b]+ for {Mn}a or {Mn}b  Mn(CO)3( N N ) or Mn(CO)2(bipy)(P(OPh)3). In the same way the salt [fac-Mn(CO)3(bipy)2(/μ-SCN)]- PF6 can be prepared from fac-[Mn(NCSXCO)3(bipy)] and fac-[MnBr(CO)3(bipy)]. The structure of the compound [fac-Mn(CO)3(phen)2(μ-CN)]PF6 has been established by X-ray diffraction. The reaction of the cyanide bridged complexes with HBF4·Et2O is also discussed.

Chemistry of di- and tri-metal complexes with bridging carbene or carbyne ligands. Part 28. Synthesis and X-ray crystal structures of the compounds [MoW2(µ-CR)2(µ-CO)2(CO)4(η-C5H5)2] and [AuW2(µ-CR)2(CO)4(η-C5H5)2][PF6](R = C6H4Me-4)

The compound [W(CR)(CO)2(η-C5H5)](R = C6H4Me-4) reacts readily with the complexes [M(CO)3(NCMe)3](M = Mo or W) in hexane at reflux to afford the trimetal compounds [MW2(µ-CR)2(µ-σ:η2-CO)2(CO)4(η-C5H5)2], n.m.r. and i.r. data for which are reported. The molybdenum–ditungsten compound was fully characterised structurally by a single-crystal X-ray diffraction study. It comprises a bent W–Mo–W spine [148.2(2)°] with the Mo–W bonds [2.938(1)A] bridged by CC6H4Me-4 groups. The Mo atom carries two terminal carbonyl ligands; the bisector of the angle between these is an approximate axis of two-fold symmetry for the molecule as a whole. The two molybdenum–tungsten–carbene ring systems are not coplanar, but are twisted relative to one another so that the two planes are nearly orthogonal. The Mo–W and Mo–C(carbene) bonds do not form a pseudo-tetrahedral group, however, because of the presence of two cis carbonyl ligands on the central Mo atom. An especially interesting feature is that, of the two terminal carbonyl ligands on each tungsten atom, one is η2-bonded to the central molybdenum atom. The significance of this is discussed. Crystals are triclinic, space group P(no. 2), and the structure has been refined to R= 0.038 for 3 711 intensities measured to 2θ= 55° at 210 K. Treatment of chloro(tetrahydrothiophene)gold(I) with [W(CR)(CO)2(η-C5H5)] in tetrahydrofuran in the presence of TIPF6 affords the salt [AuW2(µ-CR)2(CO)4(η-C5H5)2][PF6], while [Ag(NCMe)4][BF4] and [W(CR)(CO)2(η-C5H5)] give [AgW2(µ-CR)2(CO)4(η-C5H5)2][BF4]. The spectroscopic data (i.r. and n.m.r.) for these gold and silver compounds are discussed, and the structure of the former has been established by X-ray diffraction. The cation has a bent W–Au–W spine [162.8(1)°] with the Au–W bonds [2.752(1)A] bridged by the CC6H4Me-4 groups. The dihedral angle between the two dimetallacyclopropene rings is 62°. The tungsten atoms carry η-C5H5 groups and two terminally bound CO ligands. Crystals are orthorhombic, space group Pnna(no. 52), and the structure has been refined to R= 0.050 for 1 654 reflections measured to 2θ= 50° at 200 K.

Synthesis and spectroscopic properties of a new high molecular weight poly-spirophosphazene-oxypyridine copolymer and its complexes with W(CO)5 fragments

Abstract The polyspirophosphazene copolymer {[NP(O 2 C 12 H 8 )] 0.7 [NP(OC 5 H 4 N) 2 ] 0.3 } n ( 2 ); that carries pyridine side groups has been prepared from [NPCl 2 ] n , by reaction first with 2,2′-dihydroxybiphenyl and potassium carbonate in THF to give a solution of the partially substituted polymer {[NP(O 2 C 12 H 8 )] 0.7 [NPCl 2 ] 0.3 } n ( 1 ), followed by the reaction of the latter with 4-hydroxypyridine (HOC 5 H 4 N) also in the presence of potassium carbonate. The reaction of ( 2 ) with [W(HOMe)(CO) 5 ] in a CH 2 Cl 2 –MeOH mixture gave the polymeric complex {[NP(O 2 C 12 H 8 )] 0.7 [NP(OC 5 H 4 NW(CO) 5 ) 2 ] 0.3 } n ( 4 ), that, upon treatment with NCMe in THF produced derivatives with less metal carbonyl contents.

The chemical and electrochemical oxidation of pyridonate-bridged ruthenium(I) dimers. X-Ray structure of [Ru2(μ-pyO)2(CO)4(pyOH)2] (pyOH = 2-pyridone)

Abstract Chemical and electrochemical studies have shown that the pyridonate-bridged ruthenium(I) dimers [Ru 2 (μ-pyO) 2 (CO) 4 (L) 2 ] ( 1 ) (L = PPh 3 , 1a ; P i Pr 3 , 1b ; or pyOH, 1c ; pyOH = 2-pyridone) can be oxidized to the cationic paramagnetic species [Ru 2 (μ-pyO) 2 (CO) 4 (L) 2 ] + ( 2 ). The species 2 are very unstable at room temperature, decomposing into a mixture of 1 and the ruthenium(II) cations [Ru(pyO)(CO) 2 (L)] + ( 3 ). The latter can be obtained quantitatively by reaction of 1 with two equivalents of oxidant. The structure of complex 1c , which has an oxidant peak in its cyclic voltammogram at an unexpectedly high potential (1.11 versus 0.47 V for 1a and 0.33 V for 1b ), has been determined by X-ray crystallography, revealing the presence of two intramolecular hydrogen bonds between the oxygen. atoms of the bridging and the terminal pyO fragments.