A Tetranuclear Manganese Cluster with a Star-Shaped Mn4O6 Core Motif: Directed Synthesis using a Mononuclear Precursor Complex

Abstract

The tetranuclear manganese(II) complex [Mn 4 (ppi) 6 ](BPh 4 ) 2 (2) (Hppi ϭ 2-pyridylmethyl-2-hydroxyphenylimine) is prepared by using the precursor complex [Mn(ppi) 2 ]·H 2 O (1). Based on UV/Vis-and IR-spectroscopy data in combination with mass spectrometry it has been concluded that 1 is a mononuclear neutral Mn II complex, in which two ppi ligands chelate the manganese atom. Compound 2 crystallizes in the triclinic space group P1 (no. 2), with a ϭ 17.500 (3), b ϭ 17.955(4), c ϭ 19.101(4) Å , α ϭ 113.79(3)°, β ϭ 111.33(3)°, γ ϭ 93.91(3)°, V ϭ 4950(2) Å 3 and Z ϭ 2. In the tetranuclear [Mn 4 (ppi) 6 ] 2ϩ comEin vierkerniger Mangancluster mit einer sternförmigen Mn 4 O 6 -Kernstruktur: Gezielte Synthese mit einem mononuklearen Precursorkomplex Inhaltsübersicht. Mit der Darstellung von [Mn 4 (ppi) 6 ](BPh 4 ) 2 (2) (Hppi ϭ 2-Pyridylmethyl-2-hydroxyphenylimin) unter Verwendung des Precursorkomplexes [Mn(ppi) 2 ]·H 2 O (1) ist die gezielte Synthese eines vierkernigen Mangan(II)-Clusters gelungen. Anhand von UV/Vis-und IR-spektroskopischen Daten sowie des Massenspektrums wurde 1 als ein mononuklearer Mn II -Neutralkomplex identifiziert, in dem zwei ppi-Liganden das Manganion umgeben. Die Verbindung 2 kristallisiert im triklinen Kristallsystem in der Raumgruppe P1 (Nr. 2) mit a ϭ 17.500(3), b ϭ 17.955(4), c ϭ 19.101(4) Å , α ϭ 113.79(3)°, β ϭ 111.33(3)°, γ ϭ 93.91(3)°, V ϭ

Spin Crossover in cis Manganese(III) Quinolylsalicylaldiminates

“…The absorption bands at 457–458 nm and 328–330 nm are assigned to ligand‐to‐metal charge transfer (LMCT) bands from the phenolate oxygen p π to d π * and d σ * metal orbitals, respectively. Similar findings have been reported in other Mn Schiff base complexes 31,32. The Mn III compounds 1 + and 2 + show a shift in both bands especially the lower energy O p π to Mn d π * band which lowers by ca.…”

“…The Mn–N and Mn–O bond lengths of these complexes are between 2.273(3)–2.288(5) and 2.059(4)–2.087(3) Å, respectively. Interestingly, unlike the [Mn(pap) 2 ] {pap = 2‐(pyridin‐2‐ylmethyleneamino)phenolate} fragment in [Mn 4 (pap) 6 ] 2+ the imine and quinoline Mn–N bonds are almost identical suggesting that the (6,5) membered chelate rings of the qsal ligand result in a more symmetric coordination 32. Direct comparisons with the pyridyl complexes [Mn(salimp) 2 ] {salimp = 2‐[(pyridin‐2‐ylmethylimino)methyl]phenolate} are difficult as structures of these compounds are only reported as the Mn III species 34.…”

Star-Shaped Molecule of MnII4O6 Core with an St = 10 High-Spin State. A Theoretical and Experimental Study with XPS, XMCD, and Other Magnetic Methods

“…The molecular ion peak at m/z 449 (81.7%), together with the fragments at m/z 371 (49.2%), 252 (100%), 196 (68.9%), 173 (24.2%), 120 (35%), and 109 (26.3%), clearly indicates the identity of the precursor [MnL H 2 ] 0 . Because the manganese precursor, prepared in a different way, has been reported 31 without any structural parameters, we grew single crystals of the compound with the 2-methyl derivative (Figure 2) of the ligand (HL CH 3 ) for the structure determination. Figure 4 2+ , tetrafluoroborate anions, acetonitrile, and water as solvent molecules of crystallization.…”

The group 13 metal complexes of sterically-hindered substituted iminophenol: synthesis and structure

“…6,7 The versatility of the Schiff base ligands may be illustrated by the tridentate species HL1 (Scheme 1), 8 which is known to form complexes with Fe(III), Co(III), Ni(II), Zn(II), Cd(II), Ga(III), In(III) and lanthanide(III) ions. [9][10][11][12][13][14][15][16] The complexes of Zn(II), Cd(II), Ga(III) and In(III) show intense luminescence at room temperature and thus have potential applications as photoactive materials. 9 The Schiff bases derived from a large number of carbonyl compounds and amines have already been known.…”