Structure of cis-dichlorobis(1,10-phenanthroline)manganese(II) and cis-dichlorobis(2,2´-bipyridine)manganese(II) (original) (raw)
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Synthesis and Crystal Structure of Manganese(II) Bipyridine Carboxylato Complexes: (bipy)2MnII(μ-C2H5CO2)2MnII(bipy)22 and [MnII(ClCH2CO2)(H2O)(bipy)2]ClO4 · H2O (bipy = 2,2′-bipyridine)
Zeitschrift für anorganische und allgemeine Chemie, 2001
Two manganese(II) bipyridine carboxylate complexes, [(bipy) 2 Mn II (l-C 2 H 5 CO 2 ) 2 Mn II (bipy) 2 } 2 ](ClO 4 ) 2 (1), and [Mn II (ClCH 2 CO 2 )(H 2 O)(bipy) 2 ]ClO 4´H2 O (2) were prepared. 1 crystallizes in the triclinic space group P 1 with a = 8.604 , b = 12.062(3), c = 13.471(3) A Ê , a = 112.47(2), b = 93.86(2), c = 92.87(3)°, V = 1211.1(6) A Ê 3 and Z = 1. In the dimeric, cationic complex with a crystallographic center of symmetry two 2,2'-bipyridine molecules chelate each manganese atom. These two metal fragments are then bridged by two propionato groups in a syn-anti conformation. The Mn´´´Mn distance is 4.653 A Ê . 2 crystallizes in the mono-clinic space group P2 1 /c with a = 9.042(1), b = 13.891(1), c = 21.022(3) A Ê , b = 102.00(1)°, V = 2569.3(5) A Ê 3 and Z = 4.
Inorganica Chimica Acta, 2009
Manganese(II) complexes, Mn 2 L 1 3 (ClO 4 ) 4 , MnL 1 (H 2 O) 2 (ClO 4 ) 2 , MnL 2 (H 2 O) 2 (ClO 4 ) 2 , and {(l-Cl)MnL 2 (PF 6 )} 2 based on N,N 0 -bis(2-pyridinylmethylene) ethanediamine (L 1 ) and N,N 0 -bis(2-pyridinylmethylene) propanediamine (L 2 ) ligands have been prepared and characterized. The single crystal X-ray diffraction analysis of Mn 2 L 2 3 (ClO 4 ) 4 shows that each of the two Mn(II) ion centers with a Mn-Mn distance of 7.15 Å are coordinated by one ligand while a common third ligand bridges the metal centers. Solid-state magnetic susceptibility measurements as well as DFT calculations confirm that each of the manganese centers is high-spin S = 5/2. The electronic structure obtained shows no orbital overlap between the Mn(II) centers indicating that the observed weak antiferromagentism is a result of through space interactions between the two Mn(II) centers. Under different reaction conditions, L 1 and Mn(II) yielded a one-dimensional polymer, MnL 1 (H 2 O) 2 (ClO 4 ) 2 . Ligand L 2 when reacted with manganese(II) perchlorate gives contrarily to L 1 mononuclear MnL 2 (H 2 O) 2 (ClO 4 ) 2 complex. The analysis of the structural properties of the MnL 2 (H 2 O) 2 (ClO 4 ) 2 lead to the design of dinuclear complex {(l-Cl)MnL 2 (PF 6 )} where two chlorine atoms were utilized as bridging moieties. This complex has a rhomboidal Mn 2 Cl 2 core with a Mn-Mn distance of 3.726 Å. At room temperature {(l-Cl)MnL 2 (PF 6 )} is ferromagnetic with observed l eff = 4.04 l B per Mn(II) ion. With cooling, l eff grows reaching 4.81 l B per Mn(II) ion at 8 K, and then undergoes ferromagnetic-to-antiferromagnetic phase transition.
Inorganic Chemistry, 2002
The reaction of the bis-chelating ligand 1,2-bis(2,2′-bipyridine-6-yl)ethane (L) with the trinuclear species of formula [Mn 3 O(O 2 CR) 6 (py) 3 ](ClO 4 ) (R ) Me (1); R ) Et (2); R ) Ph ) has afforded the new tetranuclear mixed-valent complexes [Mn 4 O 2 (O 2 CR) 4 L 2 ](ClO 4 ) 2 (R ) Me (4); R ) Et (5); R ) Ph (6)) and [Mn 4 O 2 (OMe) 3 (O 2 CR) 2 L 2 (MeOH)]-(ClO 4 ) 2 (R ) Me (7); R ) Et (8); R ) Ph (9)). Complexes 4−6 were obtained in yields of 20%, 44%, and 37%, respectively. They are mixed-valent, with an average Mn oxidation state of +2.5. Complexes 7−9 were obtained in yields of 57%, 65%, and 70%, respectively. They are also mixed-valent, but with an average Mn oxidation state of +2.75. Complexes 4‚2THF and 9‚3MeOH‚H 2 O crystallize in the triclinic space group P1 h and contain [Mn 4 (µ 3 -O) 2 ] 6+ and [Mn 4 (µ 3 -O) 2 (µ-OMe) 2 ] 5+ cores, respectively, the latter being a new structural type in the family of Mn 4 complexes. Reactivity studies of 4−9 have shown that 4−6 can be converted into 7−9, respectively, and vice versa. The magnetic properties of 5 and 9 have been studied by dc and ac magnetic susceptibility techniques. Complex 5 displays antiferromagnetic coupling between its Mn ions resulting in a spin ground state of S ) 0. Complex 9 also displays antiferromagnetic coupling, but the resulting ground state is S ) 7 / 2 , as confirmed by fitting magnetization versus field data collected for 9 at low temperatures, which gave S ) 7 / 2 , D ) −0.77 cm -1 , and g ) 1.79. Complex 9 exhibits a frequency-dependent out-of-phase ac susceptibility peak, indicative of the slow magnetization relaxation that is diagnostic of single-molecule magnetism behavior. Figure 4. Plot of MT vs temperature for complex 5. M is the dc magnetic susceptibility measured in a 10 kG field.
Polyhedron, 1994
The title complex was synthesized by oxidizing manganese(I1) with (NH4)2Ce(N03)6 in acetic acid in the presence of the ligand. The structure of the complex was determined by X-ray crystallography. The nitrate ion and acetic acid molecules are severely disordered. The cis-MnN,Cl, coordination sphere is Jahn-Teller distorted, the axial Mn-N(2) (2.23 1 A) bond being longer than the equatorial Mn-N(1) (2.073 A) bond. Structural comparisons are made with the analogous manganese(I1) complex Mn(bpy),Cl,. The observed optical and EPR spectra show that the complex undergoes disproportionation in various solvents giving manganese(II1, IV) species.
Inorganic …, 1991
The synthesis and characterization of several new bis(r-oxo)dimanganese(III,IV) and -(IV,IV) complexes employing tetradentate ligands related to N,N'-bis(2-pyridylmethyl)-1,2-ethanediamine (bispicen) (1) are reported. The crystal structure of one MnIV2 complex, bis(p-oxo)bis[N,N'-bis(2-pyridylmethyl)-1,3-propanediamine]dimanganese(IV,IV) perchlorate trihydrate, [(bispictn)-Mn-02-Mn(bispictn)] (C104)4.3H20 (14), has been established by three-dimensional X-ray diffraction techniques. The complex, of formula Mn2C30H44N8020C1 , crystallizes in the monoclinic space group P21/c with four molecules in a cell of dimensions a = 12.772 (7) A, b = 18.581 (7) 1, c = 18.816 (6) A, and @ = 108.81 (3)'. The structure was solved by direct methods and refined by least-squares techniques to a final agreement factor of 0.0564 based on 2247 observed independent intensities. The structure is similar to that of the bispicen analogue, but the Mn-Mn distance of 2.719 (3) A is longer than that of 2.672 (1) A in the bispicen complex, and the bridging Mn-0-Mn angles of 98.4 (4) and 97.3 (4)' are larger than those of 95.0 (2) and 95.2 (2)' in the bispicen complex. The magnetic properties of the (II1,IV) complexes are consistent with a doublet ground state, the observed J values being similar to those observed in other (II1,IV) complexes. The (IVJV) complexes have singlet ground states, with J values again consistent with those in other systems. The EPR spectra of the (II1,IV) complexes exhibit the commonly occurring 16-line spectrum, with varying degrees of anisotropy depending on the particular ligand system. The complexes all exhibit two quasi-reversible waves in the cyclic voltammograms, with redox potentials in the range 0.083-0.170 and 0.943-1.008 V (vs Ag/AgCl) for the (111,111)
Polyhedron, 1997
Ahstract-3,6,9-trioxaundecanedioic acid (3,6,9-tddaH2) reacts with Mn(CH3CO2)2"4H20 in ethanol to give [Mn(3,6,9-tdda)]'H20 (1). Recrystallization of 1 from methanol gives crystals of [Mn(3,6,9-tdda) (H20)2]'2H20 (2). Complex 1 reacts with an ethanolic solution of 1,10-phenanthroline (phen) to give { [Mn(3,6,9-tdda)(phen)2]" 3H20" EtOH}° (3). All of the complexes are extremely water soluble. Complexes 2 and 3 were structurally characterised. The manganese(II) ion in 2 is seven coordinate, with an approximately pentagonal bipyramidal 07 coordination sphere. The axial donors are water molecules and the pentagonal plane is occupied by the diacid, acting as a pentadentate ligand through the three ethereal oxygens and one oxygen atom from each of the carboxylate functions. In complex 3 the manganese(II) ion is six-coordinate, being bound to two bidentate phenanthroline ligands and to the carboxylate oxygen atoms from two symmetry related diacids which are coordinated in a eis fashion. The structure consists of polymeric chains, with diacid ligands bridging the manganese ions. There is n-n stacking of pairs of phenanthroline ligands on adjacent chains, running along both the z and y directions.
Inorganic Chemistry, 2003
and R ) Me (3), Et (5), or C 2 H 4 Cl (6); and X ) F -, R ) Me (4)] were prepared by a slightly modified procedure that includes the addition of HClO 4 . For the preparation of 4, MnF 2 was employed instead of MnCl 2 ‚4H 2 O. [Mn 2 O 2 (O 2 -CMe)Cl 2 (bpy) 2 ] 2 [MnCl 4 ]‚2CH 2 Cl 2 (1‚2CH 2 Cl 2 ) crystallizes in the monoclinic space group C2/c with a ) 21.756(2) Å, b ) 12.0587 Å, c ) 26.192(2) Å, R ) 90°, ) 111.443(2)°, γ ) 90°, V ) 6395.8(6) Å 3 , and Z ) 4. [Mn 2 O 2 (O 2 CMe)Cl(H 2 O)(bpy) 2 ](NO 3 ) 2 ‚H 2 O (2‚H 2 O) crystallizes in the triclinic space group P1 h with a ) 11.907(2) Å, b ) 12.376(2) Å, c ) 10.986(2) Å, R ) 108.24(1)°, ) 105.85(2)°, γ ) 106.57(1)°, V ) 1351.98(2) Å 3 , and Z ) 2. [Mn 2 O 2 (O 2 CMe)Cl(H 2 O)(bpy) 2 ](ClO 4 ) 2 ‚MeCN (3‚MeCN) crystallizes in the triclinic space group P1 h with a ) 11.7817(7) Å, b ) 12.2400(7) Å, c ) 13.1672(7) Å, R ) 65.537(2)°, ) 67.407(2)°, γ ) 88.638(2)°, V )
Transition Metal Chemistry, 2005
A series of mononuclear MnII and MnIV complexes of general formulae [MnL2(NCS)2] (1a–1d) and [Mn(L′)2(NCS)2] (2a–2c) have been prepared where L are Schiff bases obtained by the condensation of pyridine-2-aldehyde with para-alkyl-substituted aniline, and L′ are the corresponding amide ligands. The room temperature magnetic susceptibility data of (1a–1d) indicate that MnII is in a high spin state. The cyclic voltammograms of (1a–1d) exhibit a one-electron quasi-reversible MnII→MnIII oxidation. A linear correlation has been found when E 0[MnIII/MnII] is plotted against Hammett σ p parameters. X-ray crystallographic data of (1b) shows that the central MnII ion adopts a distorted octahedral geometry with six different Mn–N distances. Upon oxidation of MnII complexes (1b–1d) by H2O2, the corresponding MnIV complexes (2a–2c) were obtained, and the Schiff base ligands were oxidized to the corresponding amides. The lowest energy LMCT bands of these MnIV complexes correlate linearly with Hammett σ p parameters. The redox behavior of the MnIV complexes has been investigated by cyclic voltammetry. E.p.r. spectra of the MnII and MnIV complexes are also reported.
Heptanuclear and Decanuclear Manganese Complexes with the Anion of 2-Hydroxymethylpyridine
Inorganic Chemistry, 2003
The synthesis and magnetic properties are reported of two new clusters [Mn 10 O 4 (OH) 2 (O 2 CMe) 8 (hmp) 8 ](ClO 4 ) (1) and [Mn 7 (OH) 3 (hmp) Cl 3 ](Cl)(ClO 4 ) (2). Complex 1 was prepared by treatment of [Mn 3 O(O 2 CMe) 6 (py) 3 ](ClO 4 ) with 2-(hydroxymethyl)pyridine (hmpH) in CH 2 Cl 2 , whereas 2 was obtained from the reaction of MnCl 2 ‚4H 2 O, hmpH, and NBu n 4 MnO 4 in MeCN followed by recrystallization in the presence of NBu n 4 ClO 4 . Complex 1‚2py‚10CH 2 Cl 2 ‚ 2H 2 O crystallizes in the triclinic space group P1 h. The cation consists of 10 Mn III ions, 8 µ 3 -O 2ions, 2 µ 3 -OHions, 8 bridging acetates, and 8 bridging and chelating hmpligands. The hmpligands bridge through their O atoms in two ways: two with µ 3 -O atoms and six with µ 2 -O atoms. Complex 2‚3CH 2 Cl 2 ‚H 2 O crystallizes in the triclinic space group P1 h. The cation consists of four Mn II and three Mn III ions, arranged as a Mn 6 hexagon of alternating Mn II and Mn III ions surrounding a central Mn II ion. The remaining ligation is by three µ 3 -OHions, three terminal chloride ions, and nine bridging and chelating hmpligands. Six hmpligands contain µ 2 -O atoms and three contain µ 3 -O atoms. The Clanion is hydrogen-bonded to the three µ 3 -OHions. Variable-temperature direct current (dc) magnetic susceptibility data were collected for complex 1 in the 5.00−300 K range in a 5 kG applied field. The M T value gradually decreases from 17.87 cm 3 mol -1 K at 300 K to 1.14 cm 3 mol -1 K at 5.00 K, indicating an S ) 0 ground state. The ground-state spin of complex 2 was established by magnetization measurements in the 0.5−3.0 T and 1.80−4.00 K ranges. Fitting of the data by matrix diagonalization, incorporating only axial anisotropy (DŜ z 2 ), gave equally good fits with S ) 10, g ) 2.13, D ) −0.14 cm -1 and S ) 11, g ) 1.94, D ) −0.11 cm -1 . Magnetization versus dc field scans down to 0.04 K reveal no hysteresis attributable to single-molecule magnetism behavior, only weak intermolecular interactions.