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Dimeric [Mn(salpn)NCS] 2 (1) and polymeric [Mn(salpn)NCS] n (2) are formed by the reaction of Mn(CH 3 CO 2 ) 2 . 4H 2 0, the schiff base, and thiocyanate. The formation of the two polymorphic forms is solvent and temperature dependent. 1: orthorhombic, space group Pbca, with a = 12.573(2) A, b = 13.970(7) A, c = 18.891(9) A, and Z = 8. 2: orthorhombic, space group Pna2 1 , with a = 12.5277(14) A, b = 11.576(2) A, c = 11.513(2) A, and Z= 4. The dimers in 1 are held together by weak noncovalent S...π (phenyl) interactions leading to a chain along the a-axis. Each monomeric unit of the polymer in 2 is related to its adjacent ones by a 2-fold screw axis leading to a helix along the c-axis. The exchange coupling is nondetectable in the dimer. The magnetic susceptibility of the helical chain fits a classical chain law with J = -3.2 cm - 1 and shows a weak ferromagnetic ordering below 7 K due to spin canting effects.

Two structurally significant polyiodides have been synthesized as salts of manganese(II) trischelates and characterized by three-dimensional X-ray crystallographic data. The complex, [Mn(phen)3](I3)2 (1), where phen = 1,10-phenanthroline, crystallizes in the hexagonal space group R 3 with 6 mononuclear cations in a cell of dimensions, a = b = 16.456(3) A; c = 25.864(4) A. The structure has been refined to the final R1 (wR2) values of 0.0365 (0.0782) based on 1981 (F ≥ 4σF) observed independent reflections. The structure of the [Mn(phen)3]2+ cation is unexceptional, whereas there are two types of symmetric I3− ions with I–I distances of 2.828(1) and 2.912(1) A. The longer I3− ions and the trischelate cations form layers of hexagonal network, while the shorter I3− ions are present as linkages between the layers in the crystal. The complex, [Mn(bpy)3](I3)1.5(I8)0.25 (2), where bpy = 2,2′-bipyridine, crystallizes in the monoclinic space group C2/c with 8 mononuclear cations in a cell of dimensions, a = 29.321(1) A; b = 12.9177(4) A; c = 23.2863(8) A; β = 120.950(2)°. The structure has been refined to the final R1 (wR2) values of 0.0536 (0.1310) based on 4192 (F ≥ 4σF) observed independent reflections. The structure consists of [Mn(bpy)3]2+ cations, two types of I3− ions, and infinite linear polyiodide chains of the composition, (I82−)n. Powder diffuse reflectance spectra measured for the complexes are similar exhibiting features at 23.0, 20.8, 18.5 and 17.2 kK, and are characteristic of the presence of I3− ions. Room temperature magnetic susceptibility measurements gave the magnetic moments of 5.85 and 6.05 μB for 1 and 2, respectively; the values are consistent with the expected spin-only magnetic moment for high-spin d5 manganese(II) complexes. Single crystal EPR spectral measurements with the applied field aligned parallel to the trigonal or pseudo-trigonal symmetry axis of the molecules gave zero-field splitting (D) values of 0.154 cm−1 (g = 2.06) and 0.066 cm−1 (g = 2.03) for 1 and 2, respectively. A comparison of the conductivities of the complexes in a single crystal form reveals a higher anisotropic conductivity for 2, which is attributed to the presence of linear polyiodide chains.

In summary, pegylated IFNs have a longer half-life, reduced immunogenicity, better pharmacokinetics, and enhanced biological activity when compared with standard IFN. Better adherence rates are feasible because of the once weekly administration of pegylated IFN. The adverse event profile is largely comparable. The improved pharmacokinetics of pegylated IFNs, compared with standard IFN, has translated into greater efficacy with at least similar tolerability. Pegylated IFNs with ribavirin are the standard of care for treating patients with chronic HCV who have not been treated previously.

The crystal and molecular structures of [Mn(phen)-(OH2)Cl3] (1) and [Mn(acac)2(OH2)2]ClO4·2H2O (2) were determined. A comparison is made of the Jahn-Teller distortion in these compounds with those observed in other manganese(III) complexes with monodentate axial ligands.

The Ce4+ oxidation of Mn2+ in acetic acid in the presence of 2,2?-bipyridine gives the unsymmetrical complex [Mn2O(OAc)2(H2O)(NO3)(bpy) 2](ClO4) � CH3COOH. The crystal structure of the complex shows the coordination of both nitrate and water to the metal ion. Each metal centre exhibits Jahn-Teller distortion and results in two types of Mn - OOAc bonds. The formation of different high-valent manganese complexes by Ce4+ oxidation under different conditions is discussed in the light of possible disproportionation and proton-coupled electron transfer reactions. The mode of (pseudo) Jahn-Teller distortion seen in manganese(III,III) complexes having the Mn2O(OAc)2+ 2 core is reviewed. Copyright ? 1996 Elsevier Science Ltd.