Connecting cyclophosphazenes via ring N-centres with covalent linkers

Phosphorus-nitrogen compounds. Part 20: Fully substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ether derivatives

The condensation reactions of partly substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ethers, N(3)P(3)[(o-NHPhO)(2)R]Cl(4) [where R=-CH(2)CH(2)- (1) and -CH(2)CH(2)OCH(2)CH(2)- (2)] with morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) produce fully substituted morpholino (3 and 4) and 1,4-dioxa-8-azaspiro[4,5]deca (5 and 6) phosphazenes. These are the new examples of the spiro-cyclophosphazenic lariat ether derivatives with N(2)O(x) (x=2 and 3) donor type containing 11- and 14-membered macrocycles. The solid state structures of 3, 5 and 6 have been determined by X-ray diffraction techniques. Compound 3 has intermolecular N-H...O hydrogen bond, compound 5 has intra- and intermolecular N-H...O hydrogen bonds, while compound 6 has intramolecular N-H...O and O-H...N and intermolecular N-H...O and O-H...O hydrogen bonds. The correlations of the endocyclic (alpha) and exocyclic (alpha') NPN bond angles with deltaP(spiro) values are investigated. The structural investigations of 3-6 have been verified by elemental analyses, MS, FTIR, (1)H, (13)C and (31)P NMR, DEPT and HETCOR techniques.

Di- and Trinuclear Complexes Derived from Hexakis(2-pyridyloxy)cyclotriphosphazene. Unusual P−O Bond Cleavage in the Formation of [{(L‘CuCl)2(Co(NO3)}Cl] (L‘ = N3P3(OC5H4N)5(O))

Hexakis(2-pyridyloxy)cyclotriphosphazene (L) is an efficient multisite coordination ligand which binds with transition metal ions to produce dinuclear (homo- and heterometallic) complexes [L(CuCl)(CoCl3)], [L(CuCl)(ZnCl3)], [L(CoCl)(ZnCl3)], and [L(ZnCl2)2]. In these dinuclear derivatives the cyclophosphazene ligand utilizes from five to six nitrogen coordination sites out of the maximum of nine available sites. Further, the spacer oxygen that separates the pyridyl moiety from the cyclophosphazene ring ensures minimum steric strain to the cyclophosphazene ring upon coordination. This is reflected in the near planarity of the cyclophosphazene ring in all the dinuclear derivatives. In the dinuclear heterobimetallic derivatives one of the metal ions [Cu(II) or Co(II)] is hexacoordinate and is bound by the cyclophosphazene in a eta5-gem-N5 mode. The other metal ion in these heterobimetallic derivatives [Co(II) or Zn(II)] is tetracoordinate and is bound in an eta(1)-N(1) fashion. In the homobimetallic derivative, [L(ZnCl2)2], one of the zinc ions is five-coordinate (eta3-nongem-N3), while the other zinc ion is tetracoordinate(eta2-gem-N2). The reaction of L with CuCl2 followed by Co(NO3)2.6H2O yields a trinuclear heterobimetallic complex [{(L'CuCl)2Co(NO3)}Cl] [L' = N3P3(OC5H4N)5(O)]. In the formation of this compound an unusual P-O bond cleavage involving one of the phosphorus-pyridyloxy bonds is observed. The molecular structure of [{(L'CuCl)2Co(NO3)}Cl] [L' = N3P3(OC5H4N)5(O)] reveals that each of the two the P-O-cleaved L' ligands is involved in binding to Cu(II) to generate the motif L'CuCl. Two such units are bridged by a Co(II) ion. The coordination environment around the bridging Co(II) ion contains four oxygen (two P-O units, one chelating nitrate) and two nitrogen atoms (pyridyloxy nitrogens).