metal-organic compounds

Transcription

1 metal-organic compounds Acta Crystallographica Section C Crystal Structure Communications ISSN Aquachloro[N,N 0 -ethylenebis(salicylideneiminato)]manganese(iii) David MartõÂnez, Majid Motevalli and Michael Watkinson* Department of Chemistry, Queen Mary, University of London, Mile End Road, London E1 4NS, England Correspondence m.watkinson@qmul.ac.uk Received 12 December 2001 Accepted 21 February 2002 Online 21 March 2002 The title compound, aquachloro{2,2 0 -[1,2-ethanediylbis- (nitrilomethylidyne)]diphenolato- 4 O,N,N 0,O 0 }manganese(iii), [MnCl(C 16 H 14 N 2 O 2 )(H 2 O)], is a neutral manganese(iii) complex with a pseudo-octahedral metal centre. The equatorial plane comprises the four donor atoms of the tetradentate Schiff base ligand [MnÐO (4) and (4) A Ê, and MnÐN (5) and (5) A Ê ], with a water molecule [MnÐO (4) A Ê ]andacl ligand [MnÐ Cl (16) A Ê ] completing the coordination sphere. The distorted geometry is highlighted by the marked displacement of the Mn III ion out of the least-squares plane of the four Schiff base donor atoms by (2) A Ê. These monomeric Mn III centres are then linked into a polymeric array via hydrogen bonds between the coordinated water molecule and the phenolic O-atom donors of an adjacent Mn III centre [OÐ HO (5) and (5) A Ê ]. Comment Manganese±Schiff base complexes continue to be of interest, due principally to the uncertainty that still surrounds the mechanism of the Jacobsen±Katsuki epoxidation. This is a reaction that represents one of the most ef cient means for the formation of CÐO bonds in asymmetric synthesis (Jacobsen & Cavallo, 2001). However, the recent discovery of new enzymatic systems that contain a single Mn ion at their In (I), the metal centre adopts a pseudo-octahedral geometry. The equatorial plane comprises the tetradentate Schiff base ligand, with the coordination sphere being completed by an axial water molecule and a Cl ion (Fig. 1). This geometry is comparable with the analogous complex of the related bis(5-chlorosalicylidene)ethylenediamine (5-Clsalen) ligand (Horwitz et al., 1995). However, there are subtle and signi cant differences between the two structures. In the present case, the isomer is only observed in the unit cell and there are also marked differences in the axial bond lengths. This is principally re ected by the MnÐCl distance, which is (16) A Ê in (I), compared with (1) A Ê in the 5-Clsalen complex (Horwitz et al., 1995). The MnÐCl distance in (I) is more comparable with the value of (1) A Ê observed in [Mn(salpn)Cl(MeOH)] (Law et al., 1995) and re ects the effect that substituents on the aryl ring have on this distance. Electron-withdrawing substituents have previously been shown to shorten this bond length signi cantly, e.g. MnÐCl = (4) A Ê when a nitro group is positioned para to the phenolic donor (Bermejo et al., 1996), whilst electron-donating substituents lengthen it (Horwitz et al., 1995). The MnÐCl distance in (I) also compares favourably with the values observed in the related square-pyramidal Mn III ± Schiff base complexes [Mn(salen)Cl] (Pecoraro & Butler, 1986) and [Mn(salpn)Cl] (Watkinson et al., 1999) of (1) and (18) A Ê, respectively. This similarity is further emphasized by the marked displacement of (2) A Ê for the Mn III ion from the O1/N1/N2/O2 least-squares plane, which is far greater than that observed in the related octahedral complex [0.084 (3) A Ê ; Horwitz et al., 1995] and is more comparable with square±pyramidal geometry [e.g A Ê ; Pecoraro & Butler, 1986], emphasizing the distorted nature of the octahedral geometry. This shortening of the MnÐCl bond and displacement of the Mn III ion from the least-squares plane of the Schiff base donor ligand is re ected in a commensurate lengthening of the MnÐO3 distance to (4) A Ê [cf (3) A Ê ; Horwitz et al., 1995]. The angle between the least-squares planes of the aromatic rings of the ligand is 9.2 (3), which is intermediate between the analagous angles of (Pecoraro & Butler, 1986) and 3.95 (Horwitz et al., 1995) in related systems. active centres, viz. manganese lipoxygenease (Su & Oliw, 1998) and germin (Woo et al., 2000), has also served to maintain this interest. We are currently engaged in a systematic investigation of the binding modes of carboxylate donors in manganese±schiff base complexes, following earlier investigations (Watkinson et al., 1999), during which the title compound, (I), was unexpectedly isolated. Figure 1 A view of the molecular structure of (I) with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. m258 # 2002 International Union of Crystallography DOI: /S Acta Cryst. (2002). C58, m258±m260

2 metal-organic compounds In the presence of hydrogen-bond donors on the ligands, such species have been shown to form intimate dimers in the solid state (Bermejo et al., 1996). In their absence, very weakly associated dimers have also been shown to exist (Watkinson et al., 1999). In the present case, however, rather than the formation of dimers, an intricate array of hydrogen bonds Crystal data [MnCl(C 16 H 14 N 2 O 2 )(H 2 O)] M r = Monoclinic, P2 1 a = (4) A Ê b = (3) A Ê c = (5) A Ê = (2) V = (6) A Ê 3 Z =2 Data collection Enraf±Nonius CAD-4 diffractometer Non-pro led!/2 scans Absorption correction: scan (North et al., 1968) T min = 0.675, T max = measured re ections 1488 independent re ections 1324 re ections with I > 2(I) Re nement Re nement on F 2 R(F ) = wr(f 2 ) = S = re ections 184 parameters H atoms: see below D x = 1.6 Mg m 3 Mo K radiation Cell parameters from 25 re ections = 8.1±13.9 = 1.04 mm 1 T = 160 (2) K Prism, brown mm R int = max =25 h = 12! 11 k =0! 7 l =0! 13 2 standard re ections frequency: 60 min intensity decay: none w = 1/[ 2 (F o 2 ) + (0.0720P) P] where P =(F o 2 +2F c 2 )/3 (/) max < max = 0.44 e A Ê 3 min = 0.60 e A Ê 3 Absolute structure: Flack (1983) Flack parameter = 0.01 (4) Figure 2 The molecular structure of (I), showing the polymeric hydrogen-bonded array. H atoms not involved in the hydrogen bonding have been omitted for clarity. [Symmetry codes: (i) 1 x, y 1 2, z; (ii) 1 x, y, z.] Table 1 Selected geometric parameters (A Ê, ). Mn1ÐCl (16) Mn1ÐO (4) Mn1ÐO (4) Mn1ÐO (4) Mn1ÐN (5) Mn1ÐN (5) between the coordinated water molecule of one Mn centre and the two phenolic O-atom donors of an adjacent Mn centre results in the formation of a polymeric array (Fig. 2 and Table 2). As all other bond lengths and angles about the metal centres are essentially identical in these octahedral Mn III complexes (Table 1), the subtle changes in the axial bonding observed in this and other compounds further serves to emphasize the important effects that ligand substitution can have. O1ÐMn1ÐO (16) O1ÐMn1ÐO (15) O2ÐMn1ÐO (16) O1ÐMn1ÐN (17) O1ÐMn1ÐN (18) O2ÐMn1ÐN (17) O2ÐMn1ÐN (17) O3ÐMn1ÐN (16) Table 2 Hydrogen-bonding geometry (A Ê, ). O3ÐMn1ÐN (16) N1ÐMn1ÐN (2) O1ÐMn1ÐCl (12) O2ÐMn1ÐCl (12) O3ÐMn1ÐCl (12) N1ÐMn1ÐCl (12) N2ÐMn1ÐCl (13) Experimental Compound (I) was prepared whilst attempting to synthesize [Mn(salen)(O 2 CCH 3 )] by a modi ed procedure. Manganese(II) chloride (0.47 g, mol) and H 2 salen (1.00 g, mol) were added to a round-bottomed ask containing ethanol (120 ml). Triethylamine (5 drops) was added and the resulting mixture re uxed in air for 2 h before being allowed to cool to 313 K. Sodium acetate (0.31 g, mol) in absolute ethanol (5 ml) and silver tetra uoroborate (0.72 g, mol) were added, and the mixture was heated at re ux for a further 2 h. The resulting mixture was allowed to cool to room temperature and the insoluble material that had formed was removed by ltration. The ltrate was reduced in volume to ca 25 ml and layered with diethyl ether (250 ml), and the dark-brown crystalline product, (I), which resulted was collected by ltration. DÐHA DÐH HA DA DÐHA O3ÐH17O1 i (5) 160 O3ÐH16O2 i (5) 145 Symmetry codes: (i) 1 x; y 1 2 ; z. H atoms attached to C atoms were treated as riding, with CÐH distances in the range 0.95±0.99 A Ê, using SHELXL97 defaults (Sheldrick, 1997). The water H atoms were located in difference maps and included as such in the calculations. The aromatic rings were treated as rigid hexagons during the least-squares re nement. Data collection: CAD-4-PC Software (Enraf±Nonius, 1994); cell re nement: CAD-4-PC Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to re ne structure: SHELXL97 Acta Cryst. (2002). C58, m258±m260 David MartõÂnez et al. [MnCl(C 16 H 14 N 2 O 2 )(H 2 O)] m259

3 metal-organic compounds (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLUTON in PLATON (Spek, 1998); software used to prepare material for publication: WinGX (Farrugia, 1999). Supplementary data for this paper are available from the IUCr electronic archives (Reference: GG1092). Services for accessing these data are described at the back of the journal. References Bermejo, M. R., CastinÄ eras, A., Garcia-Monteagudo, J. C., Rey, M., Sousa, A., Watkinson, M., McAuliffe, C. A., Pritchard, R. G. & Beddoes, R. L. (1996). J. Chem. Soc. Dalton Trans. pp. 2935±2944. Enraf±Nonius (1994). CAD-4-PC Software. Version 1.5c beta. Enraf±Nonius, Delft, The Netherlands. Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837±888. Flack, H. D. (1983). Acta Cryst. A39, 876±881. Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Horwitz, C. P., Dailey, G. C. & Tham, F. S. (1995). Acta Cryst. C51, 815±817. Jacobsen, H. & Cavallo, L. (2001). Chem. Eur. J. 7, 800±807. Law, N. A., Machonkin, T. E., McGorman, J. P., Larson, E. J., Kampf, J. W. & Pecoraro, V. L. (1995). J. Chem. Soc. Chem. Commun. pp. 2015±2016. North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst, A24, 351± 359. Pecoraro, V. L. & Butler, W. M. (1986). Acta Cryst. C42, 1151±1154. Sheldrick, G. M. (1997). SHELXL97. University of GoÈttingen, Germany. Spek, A. L. (1998). PLATON. University of Utrecht, The Netherlands. Su, C. & Oliw, E. H. (1998). J. Biol. Chem. 273, 13072± Watkinson, M., Fondo, M., Bermejo, M. R., Sousa, A., McAuliffe, C. A., Pritchard, R. G., Jaiboon, N., Aurangzeb, N. & Naeem, M. (1999). J. Chem. Soc. Dalton Trans. pp. 31±41. Woo, E.-J., Dunwell, J. M., Goodenough, P. W., Marvier, A. C. & Pickersgill, R. W. (2000). Nature Struct. Biol. 7, 1036±1040. m260 David MartõÂnez et al. [MnCl(C 16 H 14 N 2 O 2 )(H 2 O)] Acta Cryst. (2002). C58, m258±m260

4 supporting information [ Aquachloro[N,N -ethylenebis(salicylideneiminato)]manganese(iii) David Martínez, Majid Motevalli and Michael Watkinson Computing details Data collection: CAD-4-PC Software (Enraf Nonius, 1994); cell refinement: CAD-4-PC Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLUTON in PLATON (Spek, 1998); software used to prepare material for publication: WinGX (Farrugia, 1999). Aquachloro{2,2 -[1,2-ethanediylbis(nitrilomethylidyne)]diphenolato- κ 4 O,N,N,O }manganese(iii) Crystal data [MnCl(C 16 H 14 N 2 O 2 )(H 2 O)] M r = Monoclinic, P2 1 Hall symbol: P2yb a = (4) Å b = (3) Å c = (5) Å β = (2) V = (6) Å 3 Z = 2 Data collection Enraf Nonius CAD-4 diffractometer non profiled ω/2θ scans Absorption correction: ψ scan (North et al., 1968) T min = 0.675, T max = measured reflections 1488 independent reflections Refinement Refinement on F 2 Least-squares matrix: full R[F 2 > 2σ(F 2 )] = wr(f 2 ) = S = reflections 184 parameters 1 restraint F(000) = 384 D x = 1.6 Mg m 3 Mo Kα radiation, λ = Å Cell parameters from 25 reflections θ = µ = 1.04 mm 1 T = 160 K Prism, brown mm 1324 reflections with I > 2σ(I) R int = θ max = 25.0, θ min = 1.8 h = k = 0 7 l = standard reflections every 60 min intensity decay: none H atoms treated by a mixture of independent and constrained refinement w = 1/[σ 2 (F o2 ) + (0.072P) P] where P = (F o 2 + 2F c2 )/3 (Δ/σ) max < Δρ max = 0.44 e Å 3 Δρ min = 0.60 e Å 3 Absolute structure: Flack (1983) Absolute structure parameter: 0.01 (4) sup-1

5 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 ) x y z U iso */U eq Mn (7) (12) (6) (2) Cl (12) (2) (11) (3) O (3) (6) (3) (8) O (3) (6) (3) (8) O (3) (7) (3) (10) H * H * N (4) (7) (4) (9) N (4) (8) (4) (10) C (3) (6) (2) (11) C (3) (5) (3) (13) H * C (3) (5) (3) (15) H * C (3) (6) (2) (15) H * C (4) (5) (3) (13) H * C (3) (5) (3) (13) C (5) (9) (4) (12) H * C (6) (9) (5) (13) H8A * H8B * C (5) (9) (5) (12) H9A * H9B * C (5) (9) (5) (13) H * C (3) (5) (3) (11) C (3) (5) (3) (14) H * C (4) (7) (2) (16) H * C (4) (6) (3) (16) H * C (4) (5) (3) (14) H * C (3) (6) (2) (12) sup-2

6 Atomic displacement parameters (Å 2 ) U 11 U 22 U 33 U 12 U 13 U 23 Mn (4) (4) (4) (4) (3) (4) Cl (7) (8) (7) (6) (5) (6) N (2) (2) (2) (19) (18) (19) N (2) (3) (2) (2) (19) (2) O (17) (2) (17) (16) (14) (16) O (18) (2) (17) (16) (14) (17) O (2) (3) (19) (19) (17) (19) C (2) (3) (2) (3) (2) (3) C (3) (4) (3) (3) (2) (3) C (3) (4) (3) (3) (2) (3) C (3) (5) (3) (3) (2) (3) C (3) (4) (3) (3) (2) (3) C (2) (4) (3) (2) (2) (2) C (3) (3) (3) (2) (2) (2) C (3) (3) (3) (2) (2) (2) C (3) (3) (3) (3) (2) (3) C (3) (3) (3) (2) (2) (3) C (2) (3) (2) (3) (18) (3) C (3) (4) (3) (3) (2) (3) C (3) (5) (3) (3) (2) (3) C (3) (5) (3) (3) (2) (3) C (3) (4) (3) (3) (2) (3) C (2) (3) (2) (2) (2) (2) Geometric parameters (Å, º) Mn1 Cl (16) C5 C Mn1 O (4) C5 H Mn1 O (4) C6 C (6) Mn1 O (4) C7 H Mn1 N (5) C8 C (8) Mn1 N (5) C8 H8A 0.99 N1 C (6) C8 H8B 0.99 N1 C (7) C9 H9A 0.99 N2 C (7) C9 H9B 0.99 N2 C (7) C10 C (7) O1 C (4) C10 H O2 C (4) C11 C O3 H C11 C O3 H C12 C C1 C C12 H C1 C C13 C C2 C C13 H C2 H C14 C C3 C C14 H sup-3

7 C3 H C15 C C4 C C15 H C4 H O1 Mn1 O (16) C5 C6 C1 120 O1 Mn1 O (15) C5 C6 C (3) O2 Mn1 O (16) C1 C6 C (3) O1 Mn1 N (17) N1 C7 C (5) O1 Mn1 N (18) N1 C7 H O2 Mn1 N (17) C6 C7 H O2 Mn1 N (17) N1 C8 C (5) O3 Mn1 N (16) N1 C8 H8A O3 Mn1 N (16) C9 C8 H8A N1 Mn1 N (2) N1 C8 H8B O1 Mn1 Cl (12) C9 C8 H8B O2 Mn1 Cl (12) H8A C8 H8B O3 Mn1 Cl (12) N2 C9 C (4) N1 Mn1 Cl (12) N2 C9 H9A N2 Mn1 Cl (13) C8 C9 H9A C7 N1 C (5) N2 C9 H9B C7 N1 Mn (4) C8 C9 H9B C8 N1 Mn (3) H9A C9 H9B C10 N2 C (5) N2 C10 C (5) C10 N2 Mn (4) N2 C10 H C9 N2 Mn (3) C11 C10 H C1 O1 Mn (3) C12 C11 C C16 O2 Mn (3) C12 C11 C (3) H16 O3 H C16 C11 C (3) O1 C1 C (3) C13 C12 C O1 C1 C (3) C13 C12 H C2 C1 C6 120 C11 C12 H C3 C2 C1 120 C14 C13 C C3 C2 H2 120 C14 C13 H C1 C2 H2 120 C12 C13 H C4 C3 C2 120 C15 C14 C C4 C3 H3 120 C15 C14 H C2 C3 H3 120 C13 C14 H C3 C4 C5 120 C16 C15 C C3 C4 H4 120 C16 C15 H C5 C4 H4 120 C14 C15 H C6 C5 C4 120 O2 C16 C (3) C6 C5 H5 120 O2 C16 C (3) C4 C5 H5 120 C15 C16 C Hydrogen-bond geometry (Å, º) D H A D H H A D A D H A O3 H17 O1 i (5) 160 sup-4

8 O3 H16 O2 i (5) 145 Symmetry code: (i) x+1, y 1/2, z. sup-5