Structural, magnetic, and spectroscopic studies of tetrakis(pyridine) complexes of iron(II) sulfonates

Abstract

. 64, 429 (1986).The iron(I1) complexes Fe(NC5H5)4(RS03)2 where R = CF3, CH,, and p-CH3C6H4 have been prepared and their crystal structures determined by single crystal X-ray diffraction. Cryst$ of trans-bis(methanesulfonato-O)tetrakis(pyridine)iron(II) are monoclinic, a = 16.524(2), b = 9.1 127(6), c = 18.684(2) A, P = 109.903(6)", Z = 4, space group Pn. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.034 and R,, = 0.038 for 4243 reflections with I 2 3u(4. Crystals of trans-bis(trifluoromethanesulfonato-O)tetrakis(pyridine)iron(II) are monoclinic, a = 10.456(1), b = 9.2981(8), c = 14.625(2) A, P = 96.372(6)", Z = 2, space group Pn. Structure solved and refined as above to R = 0.036, and R,, = 0.037 for 1483 reflections with 1 2 3u(4. Crystals of transbis(p-toluenesulfonato-O)tetrakis(pyridine)iron(II) are orthorhombic, a = 40.818(2), b = 9.8722(6), c = 17.3544(7) A, Z = 8, space group Fdd2. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to R = 0.030 and R,, = 0.032 for 1851 reflections with 1 2 3u(l). All three structures show discrete octahedral molecules with monodentate trans-coordinated sulfonate groups. Two crystallographically independent molecules are observed in the R = CH3 structure, the difference between them involving the orientation of the CH3S03 groups with respect to the 0-Fe-0 vector. The FeN402 chromophore in each compoundo is a tetragonally compressed octahedron (approximate D4,, Dans le trois structures, on retrouve des molCcules octaCdriques individuelles avec des groupements sulfonates monodentates coordonntes en trans. Dans la structure oh R=CH3, on observe deux moltcules qui sont cristallographiquement indtpendantes; la difftrence entre les deux implique I'orientation des groupements CH3S03 par rapport au vecteur 0-Fe-0.Dans chacun des composts, le chromophore FeN402 est un octatdre qui est comprimt d'une faqon tttragonale (symttrie approximative D4)!) et dans lequel les distances Fe-N moyennes sont 2,21, 2.23 et 2,24 A alors que les distances Fe---0 sont 2,11, 2,06 et 2,08 a respectivement pour les derives CF3, CH3 et p-CH3C6H4. On a CtudiC les composts en faisant appel aux spectroscopies vibrationnelles, tlectroniques et de Mossbauer, i des mesures de susceptibilitt magnttique et i la calorimttrie de balayage difftrentiel. Les valeurs des dtdoublements quadrupolaires obtenus a partir des spectres de Mossbauer indiquent que les trois composts existent dans un ttat fondamental 5B2,; on a analysC les donnCes de susceptibilitC magnttique (de 3 10a 4,2 K) i l'aide des modtles tant de champ cristallin que de dtdoublement i champ ztro en faisant I'hypothtse que 1'Ctat fondamental est bien celui-18.[Traduit par le journal] IntroductionWe had earlier utilized spectroscopic and magnetic techThe study of the coordinating properties of sulfonate anions, niques to investigate the coordination of Sulfonate anions in RS03-, is of interest for a number of re...

Antiferromagnetism and metamagnetism in 1,4-diazine and pyridine complexes of nickel(II)

“…Monodentate or bidentate coordination of a sulfonate group is expected to result in a splitting of the SO3 asymmetric stretching mode, u4 (33). Significant band splitting of this type is seen in all of the sulfonate complexes studied here and, based on previous work on related complexes (1,l l), the mag- nitude of the splitting is consistent with bidentate sulfonate be used to distinguish between monodentate and bidentate coordination (38).…”

“…The copper, d9, and iron, d6, studies have provided several examples of systems in which the metals are coupled antiferromagnetically. The magnitude of the coupling has been related to structural features such as metal-ligand distance and the orientation of the plane of the bridging ligand with respect to the metallligand chromophore, the latter affecting the degree of overlap between the ligand .srorbitals and the magnetic orbital(s) on the metal (2,4,7).…”

A two-dimensional copper(I) polymer containing both molecular rod and anionic bridges: synthesis and crystal structure of (µ-chloro)-(µ-pyrazine)copper(I)

“…As for the pyrazine rings, these are located on an inversion centre, being, as usual, planar within the experimental error. Nevertheless, some values of bond lengths and angles are significantly different from those found for free pyrazine (27) and bridging copper-pyrazine complexes (1)(2)(3)(4)(5)(6)(7)(8)(15)(16)(17). Moreover, comparison of pyrazine bond lengths and angles in our complex with those reported in the literature, Table 3, reveals that the distortions in-the former are of different s i m .…”

“…Nevertheless, the position of this band, when not split, gives little useful information about the pyrazine coordination mode, as has already been pointed out (6,15). The IR spectrum of our complex shows, as the most significant feature, a single band centred at 446 cm-', which corresponds to a symmetrical bridging coordinated pyrazine with not very strong interaction, its value being in the low-frequency range for bridging pyrazines (6,15,16). The remaining bands observed (experimental section) correspond to those previously assigned (15,23).…”

Crystal structure of iron(II)-benzenedisulfonate-triaqua-bis(Nmethylpyrrolidone), Fe(BDS)(H2O)3(NMP)2, C16H28FeN2O11S2

“…2.050(2) and 2.191(2) Å [27]. Within the [FeO 6 ]octahedron three H 2 Omolecules and one BDS 2-anion define an equatorial plane with the apices being occupied by NMP molecules (Fig.…”