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An inverted triplesalen ligand by a convergent synthesis and its influence on trinuclear FeIII 3 complexes

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Abstract

The inverted triplesalen ligand H6feldMe has been synthesized from 2,4,6-triformyl-phloroglucinol and a ketimine salen half-unit in a convergent synthesis. NMR, IR, and UV-vis spectroscopy reveal that this ligand is not in the O-protonated tautomer but in the N-protonated tautomer with substantial heteroradialene contribution. This ligand and the conventional triplesalen ligand \(H_6 talen^{t - Bu_2 }\) have been used to synthesize the trinuclear FeIII complexes [(feldMe)(FeCl)3] and \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\), respectively. The molecular structures of these complexes were obtained by single-crystal X-ray diffraction. Two trinuclear FeIII complexes of [(feldMe)(FeCl)3] dimerize via two Fe-phenolate bonds, whereas due to steric hindrance no dimerization is observed for \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\). The structural data also reveal some heteroradialene contribution in the trinuclear complexes. Whereas UV-vis and Mößbauer spectroscopy are not suitable to distinguish between the two complexes, FT-IR spectra show characteristic features due to the different substitution patterns of the conventional and the inverted triplesalen ligands. Another handle is provided by electrochemistry. Whereas both complexes exhibit an irreversible oxidation wave (0.94 V vs. Fc+/Fc for [(feldMe)(FeCl)3] and 0.84 V vs. Fc+/Fc for \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\), which is assigned to the oxidation of the central backbone, higher potential oxidations are reversible for \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\) but irreversible for [(feldMe)(FeCl)3]. This is attributed to the reversible oxidation of the terminal phenolates in the di-tert-butyl substituted \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\) in contrast to the mono-methyl-substituted phenolates in [(feldMe)(FeCl)3]. The magnetic properties of \(\left[ {\left( {talen^{t - Bu_2 } } \right)\left( {FeCl} \right)_3 } \right]\) reveal a very small ferromagnetic coupling with significant zero-field splitting of the FeIII S = 5/2 ions. In contrast, the dimerization of two trinuclear complexes in [(feldMe)(FeCl)3] results in antiferromagnetic interactions between the two phenolate-bridged FeIII ions, which mask the intra-trinuclear interactions transmitted by the central phloroglucinol backbone.

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References

  1. McConnell HM. Ferromagnetism in solid free radicals. J Chem Phys, 1963, 39: 1910; Longuet-Higgins HC. Some studies in molecular orbital theory I. Resonance structures and molecular orbitals in unsaturated hydrocarbons. J Chem Phys, 1950, 18: 265–274; Iwamura H. High-spin organic molecules and spin alignment in organic molecular assemblies. Adv Phys Org Chem, 1990, 26: 179–253; Cano J, Ruiz E, Alvarez S, Verdaguer M. Spin density distribution in transition metal complexes: Some thoughts and hints. Comments Inorg Chem, 1998, 20: 27–56; Dougherty DA. Spin control in organic molecules. Acc Chem Res, 1991, 24: 88–94; Karafiloglou P. Through bond interaction of two radical centers: Analysis of the spin polarization and related mechanisms in linear diradicals. J Chem Phys, 1985, 82: 3728–3740; Ovchinnikov AA. Multiplicity of the ground state of large alternant organic molecules with conjugated bonds. Theoret Chim Acta, 1978, 47: 297–304; Glaser T, Lügger T, Fröhlich R. Synthesis, crystal structures, and magnetic properties of a mono- and a dinuclear copper(II) complex of the 2,4,6-tris(2-pyridyl)-1,3,5-triazine ligand. Eur J Inorg Chem, 2004, 394–400; Lloret F, De Munno G, Julve M, Cano J, Ruiz R, Caneschi A. Spin polarization and ferromagnetism in two-dimensional sheetlike cobalt(II) polymers: [Co(L)2(NCS)2] (L = pyrimidine or pyrazine). Angew Chem Int Ed, 1998, 37: 135–138; Fernández I, Ruiz R, Faus J, Julve M, Lloret F, Cano J, Ottenwaelder X, Journaux Y, Munoz C. Ferromagnetic coupling through spin polarization in a dinuclear copper(II) metallacyclophane. Angew Chem Int Ed, 2001, 40: 3039–3042; Pardo E, Ruiz-García R, Cano J, Ottenwaelder X, Lescouezec R, Journaux Y, Lloret F, Julve M. Ligand design for multidimensional magnetic materials: A metallosupramolecular perspective. Dalton Trans, 2008, 2780–2805; Glaser T, Theil H, Heidemeier M. Spin-polarization in 1,3,5-trihydroxybenzene-bridged first-row transition metal complexes. C R Chim, 2008, 11: 1121–1136; Plaul D, Geibig D, Görls H, Plass W. Mono- and dinuclear copper(II) complexes with meta-phenylene-bridging ligands: Synthesis, structure and magnetic properties. Polyhedron, 2009, 28: 1982–1990

    Article  CAS  Google Scholar 

  2. Glaser T. Rational design of single-molecule magnets: A supramolecular approach. Chem Commun, 2011, 47: 116–130

    Article  CAS  Google Scholar 

  3. Glaser T, Gerenkamp M, Fröhlich R. Targeted synthesis of ferromagnetically coupled complexes with modified 1,3,5-trihydroxybenzene ligands. Angew Chem Int Ed, 2002, 41: 3823–3825

    Article  CAS  Google Scholar 

  4. Glaser T, Heidemeier M, Grimme S, Bill E. Targeted ferromagnetic coupling in a trinuclear copper(II) complex: Analysis of the S t = 3/2 spin ground state. Inorg Chem, 2004, 43: 5192–5194

    Article  CAS  Google Scholar 

  5. Glaser T, Heidemeier M, Fröhlich R, Hildebrandt P, Bothe E, Bill E. Trinuclear nickel complexes with triplesalen-ligands: Simultaneous occurrence of mixed valence and valence tautomerism in the oxidized species. Inorg Chem, 2005, 44: 5467–5482

    Article  CAS  Google Scholar 

  6. Glaser T, Heidemeier M, Strautmann JBH, Bögge H, Stammler A, Krickemeyer E, Huenerbein R, Grimme S, Bothe E, Bill E. Trinuclear copper complexes with triplesalen ligands: Geometric and electronic effects on the ferromagnetic coupling via the spin-polarization mechanism. Chem Eur J, 2007, 13: 9191–9206

    Article  CAS  Google Scholar 

  7. Theil H, Freiherr von Richthofen C-G, Stammler A, Bögge H, Glaser T. Ferromagnetic coupling by the spin-polarization mechanism in a trinuclear viv triplesalen complex. Inorg Chim Acta, 2008, 361: 916–924

    Article  CAS  Google Scholar 

  8. Glaser T, Heidemeier M, Weyhermüller T, Hoffmann R-D, Rupp H, Müller P. Property-oriented rational design of single-molecule magnets: A C 3-symmetric Mn6Cr complex based on three molecular building blocks with a spin ground state of S t = 21/2. Angew Chem Int Ed, 2006, 45: 6033–6037

    Article  CAS  Google Scholar 

  9. Glaser T, Heidemeier M, Krickemeyer E, Bögge H, Stammler A, Fröhlich R, Bill E, Schnack J. Exchange interactions and zero-field splittings in C3-symmetric MnIII6FeIII: using molecular recognition for the construction of a series of high spin complexes based on the triplesalen ligand. Inorg Chem, 2009, 48: 607–620

    Article  CAS  Google Scholar 

  10. Krickemeyer E, Hoeke V, Stammler A, Bögge H, Schnack J, Glaser T. Synthesis and characterization of the heptanuclear [MnIII 6CoIII]3+ triplesalen complex: Evidence for exchange pathways involving low-spin CoIII. Naturforsch Z, 2010, 65b: 295–303

    Google Scholar 

  11. Hoeke V, Gieb K, Heidemeier M, Krickemeyer E, Müller P, Chibotaru LF, Stammler A, Bögge H, Schnack J, Schröder C, Glaser T. Manuscript in preparation.

  12. Glaser T, Heidemeier M, Fröhlich R. The first trinuclear manganese triplesalen complex: Synthesis, structural, and magnetic characterization of \(\left[ {\left( {talen^{No_2 } } \right)\left\{ {Mn^{III} \left( {DMSO} \right)_2 } \right\}_3 } \right]\left( {ClO_4 } \right)_3\). C R Chim, 2007, 10: 71–78; Glaser T, Heidemeier M, Theil H, Stammler A, Bögge H, Schnack J. A MnIII triplesalen-based 1D pearl necklace: Exchange interactions and zero-field splittings in a C3-symmetric MnIII 6 complex. Dalton Trans, 2010, 39: 192–199

    Article  CAS  Google Scholar 

  13. Chong JH, Sauer M, Patrick BO, MacLachlan MJ. Highly stable keto-enamine salicylideneanilines. Org Lett, 2003, 5: 3823–3826

    Article  Google Scholar 

  14. Sauer M, Yeung C, Chong JH, Patrick BO, MacLachlan MJ. N-Salicylideneanilines: Tautomers for formation of hydrogen-bonded capsules, clefts, and chains. J Org Chem, 2006, 71: 775–788

    Article  CAS  Google Scholar 

  15. Yelamaggad CV, Achalkumar AS, Rao DSS, Prasad SK. Self-assembly of C3h and Cs symmetric keto-enamine forms of tris (N-salicyl-ideneanilines) into columnar phases: A new family of discotic liquid crystals. J Am Chem Soc, 2004, 126: 6506–6507; Riddle JA, Bollinger JC, Lee D. Escape from a nonporous solid: Mechanically coupled biconcave molecules. Angew Chem Int Ed, 2005, 44: 6689–6693; Riddle JA, Lathrop SP, Bollinger JC, Lee D. Schiff base route to stackable pseudo-triphenylenes: stereoelectronic control of assembly and luminescence. J Am Chem Soc, 2006, 128: 10986–10987; Lim Y-K, Wallace S, Bollinger JC, Chen X, Lee D. Triferrocenes built on a C3-symmetric ligand platform: Entry to redox-active pseudo-triphenylenes via chelation-driven stereoselection of triple schiff bases. Inorg Chem, 2007, 46: 1694–1703

    Article  CAS  Google Scholar 

  16. Feldscher B, Stammler A, Bögge H, Glaser T. Synthesis and characterization of a trinuclear CuII 3 complex bridged by an extended phloroglucinol-ligand: implications for a rational enhancement of ferromagnetic interactions. Dalton Trans, 2010, 39: 11675–11685

    Article  CAS  Google Scholar 

  17. Feldscher B, Stammler A, Bögge H, Glaser T. Synthesis and characterization of trinuclear square-planar NiII 3 and CuII 3 complexes of an extended phloroglucinol ligand: Experimental evidence for the relative contributions of benzene-like and radialene-like resonance structures. Polyhedron, 2011, 30: 3038–3047

    Article  CAS  Google Scholar 

  18. Mukherjee C, Stammler A, Bögge H, Glaser T. Do trinuclear triplesalen complexes exhibit cooperative effects? Synthesis, characterization, and enantioselective catalytic sulfoxidation by chiral trinuclear FeIII triplesalen complexes. Chem Eur J, 2010, 16: 10137–10149

    Article  CAS  Google Scholar 

  19. Sheldrick GM. SADABS 2008/1 SADABS 2008, Göttingen: University of Göttingen

  20. Sheldrick GM. Acta Crystallogr. 2008, A64: 112–122

    CAS  Google Scholar 

  21. The program package JulX was used for spin-Hamiltonian simulations and fittings of the data by a full-matrix diagonalization approach (Bill E, unpublished results)

  22. Hernández-Molina R, Mederos A. Comprehensive Coordination Chemistry II, Vol. 1 (Hrsg: McCleverty JA, Meyer TJ). Oxford: Elsevier, Ltd., 2004, 411–446

    Google Scholar 

  23. Lopez J, Liang S, Bu XR. Unsymmetric chiral salen Schiff bases: A new chiral ligand pool from bis-schiff bases containing two different salicylaldehyde units. Tetrahedron Lett, 1998, 39: 4199–4202; Janssen KBM, Laquierra I, Dehaen W, Parton RF, Vankelecom IFJ, Jacobs PA. A dimeric form of Jacobsen’s catalyst for improved retention in a polydimethylsiloxane membrane. Tetrahedron: Asymmetry, 1997, 8: 3481–3487

    Article  CAS  Google Scholar 

  24. Glaser T, Heidemeier M, Lügger T. The novel triplesalen ligand bridges three NiII-salen subunits in a meta-phenylene linkage. Dalton Trans, 2003, 2381–2383

  25. Böttcher A, Elias H, Eisenmann B, Hilms E, Huber A, Kniep R, Röhr C. A novel synthetic approach to asymmetric saslen, dihydrosalen, and tetrahydrosalen ligands-structures and O2-activating properties of their nickel(II) and cobalt(II) complexes. Z Naturforsch B, 1994, 49: 1089–1100

    Google Scholar 

  26. Freiherr von Richthofen C-G, Stammler A, Bögge H, Glaser T. From triplesalen to triplesalophen: Ferromagnetic interactions via spin-polarization in a trinuclear NiII triplesalophen complex. Eur J Inorg Chem, 2011, 49–52

  27. Freiherr von Richthofen C-G, Stammler A, Bögge H, Glaser T. Probing the radialene-character in triplesalophen ligands by spectroscopic and structural analysis. J Org Chem, 2012, 77: 1435–1448

    Article  CAS  Google Scholar 

  28. Freiherr von Richthofen C-G, Stammler A, Bögge H, DeGroot MW, Long JR, Glaser T. Synthesis, structure, and magnetic characterization of a C3-symmetric MnIII 3CrIII assembly: Molecular recognition between a trinuclear MnIII triplesalen complex and a fac-triscyano CrIII complex. Inorg Chem, 2009, 48: 10165–10176

    Article  Google Scholar 

  29. Claramunt RM, López C, Santa María MD, Sanz D, Elguero J. The use of NMR spectroscopy to study tautomerism. Prog Nucl Magn Reson Spectrosc, 2006, 49: 169–206

    Article  CAS  Google Scholar 

  30. Gawinecki R, Kuczek A, Kolehmainen E, OśmiaŁowski B, Krygowsi TM, Kauppinen R. Influence of bond fixation in benzo-annulated N-salicylideneanilines and their ortho-C(O)X derivatives (X = CH3, NH2, OCH3) on tautomeric equilibria in solution. J Org Chem, 2007, 72: 5598–5607

    Article  CAS  Google Scholar 

  31. Alarcón SH, Olivieri AC, Sanz D, Claramunt RM, Elguero J. Substituent and solvent effects on the proton transfer equilibrium in anils and azo derivatives of naphthol. Multinuclear NMR study and theoretical calculations. J Mol Struct, 2004, 705: 1–9

    Article  Google Scholar 

  32. Freiherr von Richthofen C-G, Feldscher B, Lippert K, Stammler A, Bögge H, Glaser T. Manuscript in preparation.

  33. Addison AW, Rao TN, Reedijk J, van Rijn J, Verschoor GC. Synthesis, structure, and spectroscopic properties of copper(II) compounds containing nitrogen-sulfur donor ligands: The crystal and molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-dithiaheptane]copper(II) perchlorate. J Chem Soc, Dalton Trans, 1984, 1349–1356

  34. Gorbitz CH, Kaboli M, Read ML, Vestli K. Benzene-1,3,5-triol at 105 K. Acta Crystallogr, 2008, 64: o2023

    Google Scholar 

  35. Shyu HL, Wei HH, Lee GH, Wang Y. Structure, magnetic properties and epoxidation activity of iron(III) salicylaldimine complexes. Dalton Trans, 2000, 915–918

  36. Lohrie M, Knoche W. Dissociation and keto-enol tautomerism of phloroglucinol and its anions in aqueous solution. J Am Chem Soc, 1993, 115: 919–924

    Article  CAS  Google Scholar 

  37. Bosnich B. An interpretation of the circular dichroism and electronic spectra of salicylaldimine complexes of square-coplanar diamagnetic nickel(II). J Am Chem Soc, 1968, 90: 627–632; Crawford SM. The ultra-violet and visible spectra of some transition metal chelates with N,N′-bis-(o-hydroxybenzylidene)ethylenediamine and N,N′-bis-(o-hydroxybenzylidene)-o-phenylenediamine and related compounds. Spectrochim Acta, 1963, 19: 255–270; Di Bella S, Fragala I, Ledoux I, Diaz-Garcia MA, Marks TJ. Synthesis, characterization, optical spectroscopic, electronic structure, and second-order nonlinear optical (NLO) properties of a novel class of donor-Acceptor bis(salicylaldiminato)nickel(II) Schiff base NLO chromophores. J Am Chem Soc,1997, 119: 9550–9557

    Article  CAS  Google Scholar 

  38. Lubben M, Meetsma A, Bolhuis F v, Feringa BL. Synthesis, crystal and molecular structures, UV/Vis spectroscopy and electrochemical properties of two iron(III) phenolate complexes. Inorg Chim Acta, 1994, 215: 123–129; Gaber BP, Miskowsk V, Spiro TG. Resonance raman-scattering from iron(III)-transferrin and copper(II)-transferrin and an Iron(III) model compound: Spectroscopic interpretation of transferrin binding-site. J Am Chem Soc, 1974, 96: 6868–6873; Flassbeck C, Wieghardt K. Synthesis of N-phenolate-functionalized macrocycles of 1,4,7-triazacyclononane and of 1-Oxa-4,7-diazacy-clononane and their coordination chemistry with Iron(III). Z Anorg Allg Chem, 1992, 608: 60–68

    Article  CAS  Google Scholar 

  39. Berry KJ, Clark PE, Murray KS, Raston CL, White AH. Structure, magnetism, and mossbauer spectrum of the 5-coordinate complex chlorobis(N-methylbenzothiohydroxamato)Iron(III). Inorg Chem, 1983, 22: 3928–3934

    Article  CAS  Google Scholar 

  40. Adam B, Bill E, Bothe E, Goerdt B, Haselhorst G, Hildenbrand K, Sokolowski A, Steenken S, Weyhermüller T, Wieghardt K. Phenoxyl radical complexes of gallium, scandium, iron and manganese. Chem Eur J, 1997, 3: 308–319; Strautmann JBH, Walleck S, Bögge H, Stammler A, Glaser T. A tailor-made ligand to mimic the active site of diiron enzymes: an air-oxidized high-valent FeIII h.s.(μ-O)2FeIV h.s. species. Chem Commun, 2011, 47: 695–697; Strautmann JBH, Freiherr von Richthofen C-G, DeBeer George S, Bothe E, Bill E, Glaser T. Highly oxidized diiron complexes: Generation, spectroscopy, and stabilities. Chem Commun, 2009, 2637–2639; Strautmann JBH, De-Beer George S, Bothe E, Bill E, Weyhermüller T, Stammler A, Bögge H, Glaser T. Molecular and electronic structures of mononuclear iron complexes using strongly electron-donating ligands and their oxidized forms. Inorg Chem, 2008, 47: 6804–6824

    CAS  Google Scholar 

  41. Gerloch M, Mabbs FE. The crystal and molecular structure of chlo ro-(NN′-bis-salicylidene-ethylenediamine)iron(III) as a hexaco-ordinate dimer. J Chem Soc A, 1967, 1900–1908; Geiß A, Vahrenkamp H. Cyanide-bridged arrays of 2, 3 and 4 metal atoms based on salene-iron complexes-syntheses, structures and metal-metal interactions. Eur J Inorg Chem, 1999, 1793–1803; Resce JL, Fanning JC. Structure of the Fe(salen)ONO2 dimer, a ferric complex with a unidentate nitrate ligand. Acta Crystallogr, 1987, C43: 2100–2104; You ZL, Zhu HL. A dinuclear Schiff base iron(III) complex with the ligand N,N′-bis (2-oxidophenylmethyleneimino) propane-1,2-diamine. Acta Cryst, 2004, E60: m1046–m1048; Roy P, Dhara K, Chakraborty J, Nethaji M, Banerjee P. Synthesis and crystal structure of an iron(II) dimeric complex. Indian J Chem Sec A, 2007, 46A: 1947–1950; Hao L, Mu C, Kong B. Bis{[mu]-2,2′-[ethane-1,2-diylbis (nitrilomethylidyne)]diphenolato}bis[(thiocyanato-[kappa]N)iron(III)]. Acta Crystallogr, 2008, E64: m1034–m1042

  42. Reiff WM, Long GJ, Baker WA. Nature of the spin states in some binuclear iron(III) complexes. J Am Chem Soc, 1968, 90: 6347–6351; Gerloch M, Mabbs FE, Richards A. The preparation and magnetic properties of some Schiff base-iron(III) halide complexes. J Chem Soc A, 1968, 112–116; Shapira Y, Liu MT, Foner S, Dubé CE, Bonitatebus PJ. Magnetization steps in [Fe(salen)Cl](2). Phys Rev B, 1999, 59: 1046–1054

    Article  CAS  Google Scholar 

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Feldscher, B., Krickemeyer, E., Moselage, M. et al. An inverted triplesalen ligand by a convergent synthesis and its influence on trinuclear FeIII 3 complexes. Sci. China Chem. 55, 951–966 (2012). https://doi.org/10.1007/s11426-012-4598-6

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