Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807039153/hk2308sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807039153/hk2308Isup2.hkl |
CCDC reference: 660260
The ligand was prepared in two steps. In the first step, the Schiff base was synthesized from 2-hydroxy acetophenone (2.72 g. 20 mmol) and 2,2'-dimethyl -1,3-propanediamine (1.02 g, 10 mmol) in MeOH (50 ml) solution. The mixture was heated until boiling temperature and left to stand on air. After one day, the yellow Schiff base was crystallized. In the second step, the Schiff base (2.0 g) was dissolved in hot MeOH (100 ml) and a piece of solid NaBH4 was added slowly to this solution until it turned colorless. The reduced Schiff base precipitated after addition of ice. The mixture was left to stand at 277 K for 1 d to obtain crystals, and then was filtered. The crystals were allowed to dry on air. For the preparation of the title complex, the ligand (0.689 g, 2 mmol) was dissolved in hot MeOH (50 ml) and the solution of phenylboronic acid (0.244 g, 2 mmol) in hot acetonitrile (40 ml.) was added. The colorless crystals of (I) were obtained by filtration after 2 d and allowed to dry on air.
H1N and H2N (for NH2) were located in difference syntheses and refined isotropically [N—H = 0.846 (19) and 0.95 (2) Å, Uiso(H) = 0.064 (5) and 0.091 (7) Å2]. The remaining H atoms were positioned geometrically, with O—H = 0.82 Å (for OH), C—H = 0.93, 0.98, 0.97 and 0.96 Å for aromatic, methine, methylene and methyl H, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C,O), where x = 1.2 for aromatic, methine and methylene H, and x = 1.5 for all other H atoms.
It has been reported by many studies that Schiff bases form mononuclear or dinuclear compounds with phenylboronic and boric acids (Burgess et al., 1999; Höpfl et al., 1998; Maciejewska et al., 1999; Mitra et al., 2006; Mitra et al., 2004). In these studies, the compounds of reduced forms of Schiff bases also exist (Mitra et al., 2006). It has been noted that tri- and tetracoordinated compounds are formed between reduced Schiff bases and organic esters of boric acid. In this study, an ONNO type Schiff base has reduced to phenol imine form with the usage of NaBH4 in MeOH media. In fact, it was aimed to prepare a new complex from reaction of Schiff base and phenylboronic acid, but Schiff base crystal which is suitable for X-ray analysis was obtained. When ligand is crystallized in the common solvents, the appropriate single crystals for X-ray analysis could not be obtained. It was concluded that first phenylboronic acid and ligand are formed an intermediate complex, which is affected the solubility of Schiff base. Hence it was inferred that this procedure could be a new recrystallization method for organic ligands. We report herein the crystal structure of the title compound, (I).
In the molecule of (I) (Fig. 1), the bond lengths and angles are generally within normal ranges (Allen et al., 1987). In the form of the Schiff base, C=N double bond is about 1.27–1.30 Å (Sanchez et al., 2004). After the reduction reaction of double bond, it was converted to mono bonds (C7—N1 [1.483 (2) Å] and C13—N2 [1.481 (2) Å]). The strong hydrogen bond between iminic nitrogen (in the form of Schiff base) and phenol group continued after reduction (Yalçın et al., 2001).
Rings A (C1—C6) and B (C15—C20) are, of course, planar and the dihedral angle between them is A/B = 89.65 (2)°.
In the crystal structure, intermolecular N—H···O and intramolecular O—H—N and N—H—O hydrogen bonds (Table 1) result in the formation of chains along the b axis (Fig. 2), in which they seem to be effective in the stabilization of the structure.
For general backgroud, see: Burgess et al. (1999); Höpfl et al. (1998); Maciejewska et al. (1999); Mitra et al. (2004, 2006); Yalçın et al. (2001). For bond-length data, see: Allen et al. (1987); Sanchez et al. (2004).
Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
C21H30N2O2 | F(000) = 744 |
Mr = 342.47 | Dx = 1.119 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5943 reflections |
a = 11.4232 (3) Å | θ = 2.3–30.5° |
b = 10.1303 (3) Å | µ = 0.07 mm−1 |
c = 18.4399 (4) Å | T = 298 K |
β = 107.753 (5)° | Needle, colorless |
V = 2032.26 (11) Å3 | 0.2 × 0.13 × 0.1 mm |
Z = 4 |
Rigaku R-AXIS RAPID-S diffractometer | 3287 reflections with I > 2σ(I) |
dtprofit.ref scans | Rint = 0.063 |
Absorption correction: multi-scan (Blessing, 1995) | θmax = 30.9°, θmin = 2.3° |
Tmin = 0.986, Tmax = 0.986 | h = −16→16 |
57575 measured reflections | k = −14→12 |
6244 independent reflections | l = −26→26 |
Refinement on F2 | H atoms treated by a mixture of independent and constrained refinement |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0883P)2 + 0.1285P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.061 | (Δ/σ)max < 0.001 |
wR(F2) = 0.207 | Δρmax = 0.19 e Å−3 |
S = 1.04 | Δρmin = −0.15 e Å−3 |
6244 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
241 parameters | Extinction coefficient: 0.016 (3) |
0 restraints |
C21H30N2O2 | V = 2032.26 (11) Å3 |
Mr = 342.47 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.4232 (3) Å | µ = 0.07 mm−1 |
b = 10.1303 (3) Å | T = 298 K |
c = 18.4399 (4) Å | 0.2 × 0.13 × 0.1 mm |
β = 107.753 (5)° |
Rigaku R-AXIS RAPID-S diffractometer | 6244 independent reflections |
Absorption correction: multi-scan (Blessing, 1995) | 3287 reflections with I > 2σ(I) |
Tmin = 0.986, Tmax = 0.986 | Rint = 0.063 |
57575 measured reflections |
R[F2 > 2σ(F2)] = 0.061 | 0 restraints |
wR(F2) = 0.207 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | Δρmax = 0.19 e Å−3 |
6244 reflections | Δρmin = −0.15 e Å−3 |
241 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.65507 (14) | 0.05781 (12) | 0.93601 (8) | 0.0828 (4) | |
H1O | 0.6018 | 0.0768 | 0.8962 | 0.124* | |
O2 | 0.20908 (13) | 0.27291 (14) | 0.74075 (8) | 0.0812 (4) | |
H2O | 0.2582 | 0.2978 | 0.7192 | 0.122* | |
N1 | 0.49252 (14) | 0.21069 (13) | 0.83918 (7) | 0.0574 (3) | |
H1N | 0.4199 (18) | 0.1886 (17) | 0.8146 (10) | 0.064 (5)* | |
N2 | 0.34204 (12) | 0.25810 (14) | 0.64438 (8) | 0.0575 (3) | |
H2N | 0.361 (2) | 0.329 (2) | 0.6160 (12) | 0.091 (7)* | |
C1 | 0.65405 (19) | 0.3908 (2) | 1.01181 (10) | 0.0720 (5) | |
H1 | 0.6049 | 0.4659 | 1.0031 | 0.086* | |
C2 | 0.7652 (2) | 0.3934 (3) | 1.06795 (12) | 0.0892 (7) | |
H2 | 0.7908 | 0.4689 | 1.0972 | 0.107* | |
C3 | 0.8377 (2) | 0.2830 (3) | 1.08019 (12) | 0.0967 (8) | |
H3 | 0.9127 | 0.2833 | 1.1186 | 0.116* | |
C4 | 0.80105 (19) | 0.1706 (3) | 1.03618 (12) | 0.0880 (6) | |
H4 | 0.8516 | 0.0966 | 1.0447 | 0.106* | |
C5 | 0.68921 (17) | 0.16917 (19) | 0.97972 (10) | 0.0679 (5) | |
C6 | 0.61266 (15) | 0.27926 (17) | 0.96746 (9) | 0.0591 (4) | |
C7 | 0.48655 (16) | 0.27559 (17) | 0.91006 (9) | 0.0618 (4) | |
H7 | 0.4574 | 0.3664 | 0.8981 | 0.074* | |
C8 | 0.39556 (19) | 0.2018 (2) | 0.94084 (12) | 0.0862 (6) | |
H8A | 0.3158 | 0.2028 | 0.9035 | 0.129* | |
H8B | 0.3912 | 0.2439 | 0.9866 | 0.129* | |
H8C | 0.4224 | 0.1121 | 0.9518 | 0.129* | |
C9 | 0.56465 (14) | 0.23663 (14) | 0.72343 (9) | 0.0519 (4) | |
C10 | 0.60725 (17) | 0.34573 (17) | 0.67959 (10) | 0.0658 (4) | |
H10A | 0.5446 | 0.4122 | 0.6642 | 0.099* | |
H10B | 0.6222 | 0.3086 | 0.6353 | 0.099* | |
H10C | 0.6816 | 0.3847 | 0.7118 | 0.099* | |
C11 | 0.66557 (16) | 0.13156 (17) | 0.74808 (10) | 0.0661 (4) | |
H11A | 0.7405 | 0.1719 | 0.7785 | 0.099* | |
H11B | 0.6785 | 0.0922 | 0.7038 | 0.099* | |
H11C | 0.6409 | 0.0648 | 0.7774 | 0.099* | |
C12 | 0.44819 (14) | 0.17011 (15) | 0.67180 (9) | 0.0550 (4) | |
H12A | 0.4668 | 0.1326 | 0.6282 | 0.066* | |
H12B | 0.426 | 0.0979 | 0.6996 | 0.066* | |
C13 | 0.23218 (15) | 0.18842 (18) | 0.59568 (10) | 0.0641 (4) | |
H13 | 0.2578 | 0.1299 | 0.561 | 0.077* | |
C14 | 0.14172 (19) | 0.2887 (2) | 0.54867 (12) | 0.0884 (6) | |
H14A | 0.1159 | 0.3468 | 0.582 | 0.133* | |
H14B | 0.0715 | 0.2435 | 0.5159 | 0.133* | |
H14C | 0.1806 | 0.3391 | 0.5184 | 0.133* | |
C15 | 0.17410 (15) | 0.10502 (18) | 0.64405 (10) | 0.0632 (4) | |
C16 | 0.12464 (17) | −0.0173 (2) | 0.61865 (13) | 0.0813 (6) | |
H16 | 0.1345 | −0.0517 | 0.5741 | 0.098* | |
C17 | 0.0609 (2) | −0.0898 (3) | 0.65776 (16) | 0.0990 (8) | |
H17 | 0.0277 | −0.1715 | 0.6396 | 0.119* | |
C18 | 0.0474 (2) | −0.0394 (3) | 0.72403 (17) | 0.1016 (8) | |
H18 | 0.0038 | −0.087 | 0.7505 | 0.122* | |
C19 | 0.09767 (19) | 0.0807 (3) | 0.75152 (12) | 0.0875 (6) | |
H19 | 0.089 | 0.1134 | 0.7967 | 0.105* | |
C20 | 0.16146 (16) | 0.1535 (2) | 0.71185 (11) | 0.0691 (5) | |
C21 | 0.54208 (16) | 0.30049 (15) | 0.79304 (9) | 0.0555 (4) | |
H21A | 0.619 | 0.3368 | 0.8251 | 0.067* | |
H21B | 0.4852 | 0.3733 | 0.776 | 0.067* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0960 (11) | 0.0667 (8) | 0.0763 (9) | 0.0131 (7) | 0.0124 (7) | −0.0003 (6) |
O2 | 0.0779 (9) | 0.0896 (10) | 0.0826 (9) | 0.0055 (7) | 0.0342 (7) | −0.0072 (7) |
N1 | 0.0613 (9) | 0.0585 (8) | 0.0518 (7) | −0.0081 (6) | 0.0166 (6) | −0.0042 (6) |
N2 | 0.0516 (7) | 0.0576 (8) | 0.0621 (8) | −0.0012 (6) | 0.0154 (6) | 0.0016 (6) |
C1 | 0.0836 (13) | 0.0765 (12) | 0.0631 (10) | −0.0157 (10) | 0.0333 (9) | −0.0123 (9) |
C2 | 0.0855 (15) | 0.1143 (18) | 0.0714 (12) | −0.0345 (14) | 0.0292 (11) | −0.0239 (12) |
C3 | 0.0632 (12) | 0.153 (2) | 0.0696 (12) | −0.0242 (14) | 0.0133 (10) | −0.0096 (14) |
C4 | 0.0650 (12) | 0.1197 (18) | 0.0743 (12) | 0.0107 (12) | 0.0136 (10) | 0.0034 (12) |
C5 | 0.0672 (11) | 0.0762 (11) | 0.0596 (9) | −0.0021 (9) | 0.0185 (8) | −0.0016 (8) |
C6 | 0.0619 (9) | 0.0672 (10) | 0.0515 (8) | −0.0046 (8) | 0.0222 (7) | −0.0038 (7) |
C7 | 0.0648 (10) | 0.0678 (10) | 0.0555 (9) | 0.0005 (8) | 0.0223 (8) | −0.0035 (7) |
C8 | 0.0695 (12) | 0.1258 (18) | 0.0692 (11) | −0.0129 (12) | 0.0297 (10) | −0.0042 (11) |
C9 | 0.0525 (8) | 0.0499 (8) | 0.0542 (8) | −0.0012 (6) | 0.0175 (6) | −0.0008 (6) |
C10 | 0.0642 (10) | 0.0676 (10) | 0.0680 (10) | −0.0069 (8) | 0.0239 (8) | 0.0051 (8) |
C11 | 0.0620 (10) | 0.0659 (10) | 0.0699 (10) | 0.0075 (8) | 0.0192 (8) | −0.0002 (8) |
C12 | 0.0568 (9) | 0.0522 (8) | 0.0566 (8) | 0.0005 (7) | 0.0179 (7) | −0.0043 (7) |
C13 | 0.0528 (9) | 0.0762 (11) | 0.0615 (9) | −0.0068 (8) | 0.0148 (7) | −0.0012 (8) |
C14 | 0.0641 (11) | 0.1088 (16) | 0.0826 (13) | −0.0033 (11) | 0.0081 (10) | 0.0301 (12) |
C15 | 0.0496 (8) | 0.0690 (10) | 0.0691 (10) | 0.0006 (7) | 0.0154 (7) | 0.0088 (8) |
C16 | 0.0647 (11) | 0.0791 (13) | 0.0945 (14) | −0.0097 (10) | 0.0160 (10) | 0.0026 (11) |
C17 | 0.0769 (14) | 0.0833 (15) | 0.127 (2) | −0.0152 (11) | 0.0160 (14) | 0.0230 (14) |
C18 | 0.0696 (13) | 0.117 (2) | 0.1165 (19) | −0.0062 (13) | 0.0258 (13) | 0.0496 (16) |
C19 | 0.0674 (12) | 0.1145 (17) | 0.0850 (13) | 0.0118 (12) | 0.0297 (10) | 0.0290 (13) |
C20 | 0.0537 (9) | 0.0791 (12) | 0.0752 (11) | 0.0087 (8) | 0.0204 (8) | 0.0151 (9) |
C21 | 0.0601 (9) | 0.0494 (8) | 0.0556 (8) | −0.0038 (7) | 0.0157 (7) | −0.0022 (6) |
O1—C5 | 1.372 (2) | C9—C10 | 1.534 (2) |
O1—H1O | 0.82 | C10—H10A | 0.96 |
O2—C20 | 1.366 (2) | C10—H10B | 0.96 |
O2—H2O | 0.82 | C10—H10C | 0.96 |
N1—C21 | 1.472 (2) | C11—H11A | 0.96 |
N1—C7 | 1.483 (2) | C11—H11B | 0.96 |
N1—H1N | 0.846 (19) | C11—H11C | 0.96 |
N2—C12 | 1.465 (2) | C12—C9 | 1.536 (2) |
N2—C13 | 1.481 (2) | C12—H12A | 0.97 |
N2—H2N | 0.95 (2) | C12—H12B | 0.97 |
C1—C2 | 1.372 (3) | C13—C14 | 1.518 (3) |
C1—H1 | 0.93 | C13—H13 | 0.98 |
C2—H2 | 0.93 | C14—H14A | 0.96 |
C3—C2 | 1.370 (4) | C14—H14B | 0.96 |
C3—C4 | 1.386 (3) | C14—H14C | 0.96 |
C3—H3 | 0.93 | C15—C16 | 1.383 (3) |
C4—H4 | 0.93 | C15—C20 | 1.391 (3) |
C5—C4 | 1.380 (3) | C15—C13 | 1.520 (2) |
C6—C1 | 1.390 (2) | C16—H16 | 0.93 |
C6—C5 | 1.392 (3) | C17—C18 | 1.376 (4) |
C6—C7 | 1.506 (2) | C17—C16 | 1.382 (3) |
C7—C8 | 1.524 (3) | C17—H17 | 0.93 |
C7—H7 | 0.98 | C18—H18 | 0.93 |
C8—H8A | 0.96 | C19—C18 | 1.375 (4) |
C8—H8B | 0.96 | C19—H19 | 0.93 |
C8—H8C | 0.96 | C20—C19 | 1.391 (3) |
C9—C21 | 1.528 (2) | C21—H21A | 0.97 |
C9—C11 | 1.533 (2) | C21—H21B | 0.97 |
C5—O1—H1O | 109.5 | H10B—C10—H10C | 109.5 |
C20—O2—H2O | 109.5 | C9—C11—H11A | 109.5 |
C21—N1—C7 | 111.39 (13) | C9—C11—H11B | 109.5 |
C21—N1—H1N | 109.9 (12) | H11A—C11—H11B | 109.5 |
C7—N1—H1N | 106.8 (12) | C9—C11—H11C | 109.5 |
C12—N2—C13 | 112.24 (14) | H11A—C11—H11C | 109.5 |
C12—N2—H2N | 110.3 (13) | H11B—C11—H11C | 109.5 |
C13—N2—H2N | 108.4 (13) | N2—C12—C9 | 114.61 (13) |
C2—C1—C6 | 122.0 (2) | N2—C12—H12A | 108.6 |
C2—C1—H1 | 119 | C9—C12—H12A | 108.6 |
C6—C1—H1 | 119 | N2—C12—H12B | 108.6 |
C3—C2—C1 | 118.9 (2) | C9—C12—H12B | 108.6 |
C3—C2—H2 | 120.6 | H12A—C12—H12B | 107.6 |
C1—C2—H2 | 120.6 | N2—C13—C14 | 109.33 (16) |
C2—C3—C4 | 121.0 (2) | N2—C13—C15 | 110.49 (14) |
C2—C3—H3 | 119.5 | C14—C13—C15 | 111.35 (15) |
C4—C3—H3 | 119.5 | N2—C13—H13 | 108.5 |
C5—C4—C3 | 119.7 (2) | C14—C13—H13 | 108.5 |
C5—C4—H4 | 120.1 | C15—C13—H13 | 108.5 |
C3—C4—H4 | 120.1 | C13—C14—H14A | 109.5 |
O1—C5—C4 | 118.94 (18) | C13—C14—H14B | 109.5 |
O1—C5—C6 | 120.74 (16) | H14A—C14—H14B | 109.5 |
C4—C5—C6 | 120.31 (18) | C13—C14—H14C | 109.5 |
C1—C6—C5 | 118.12 (17) | H14A—C14—H14C | 109.5 |
C1—C6—C7 | 120.96 (16) | H14B—C14—H14C | 109.5 |
C5—C6—C7 | 120.88 (15) | C16—C15—C20 | 118.47 (18) |
N1—C7—C6 | 109.83 (14) | C16—C15—C13 | 120.38 (17) |
N1—C7—C8 | 109.31 (15) | C20—C15—C13 | 120.99 (16) |
C6—C7—C8 | 111.43 (14) | C17—C16—C15 | 121.7 (2) |
N1—C7—H7 | 108.7 | C17—C16—H16 | 119.2 |
C6—C7—H7 | 108.7 | C15—C16—H16 | 119.2 |
C8—C7—H7 | 108.7 | C18—C17—C16 | 119.1 (2) |
C7—C8—H8A | 109.5 | C18—C17—H17 | 120.5 |
C7—C8—H8B | 109.5 | C16—C17—H17 | 120.5 |
H8A—C8—H8B | 109.5 | C19—C18—C17 | 120.6 (2) |
C7—C8—H8C | 109.5 | C19—C18—H18 | 119.7 |
H8A—C8—H8C | 109.5 | C17—C18—H18 | 119.7 |
H8B—C8—H8C | 109.5 | C18—C19—C20 | 120.1 (2) |
C21—C9—C11 | 110.45 (13) | C18—C19—H19 | 119.9 |
C21—C9—C10 | 107.44 (13) | C20—C19—H19 | 119.9 |
C11—C9—C10 | 109.02 (14) | O2—C20—C19 | 118.30 (19) |
C21—C9—C12 | 111.75 (13) | O2—C20—C15 | 121.65 (16) |
C11—C9—C12 | 108.07 (13) | C19—C20—C15 | 120.0 (2) |
C10—C9—C12 | 110.09 (13) | N1—C21—C9 | 114.66 (12) |
C9—C10—H10A | 109.5 | N1—C21—H21A | 108.6 |
C9—C10—H10B | 109.5 | C9—C21—H21A | 108.6 |
H10A—C10—H10B | 109.5 | N1—C21—H21B | 108.6 |
C9—C10—H10C | 109.5 | C9—C21—H21B | 108.6 |
H10A—C10—H10C | 109.5 | H21A—C21—H21B | 107.6 |
C21—N1—C7—C6 | −77.69 (17) | C11—C9—C21—N1 | −65.04 (18) |
C21—N1—C7—C8 | 159.77 (15) | C10—C9—C21—N1 | 176.16 (13) |
C7—N1—C21—C9 | 173.51 (13) | C12—C9—C21—N1 | 55.30 (18) |
C13—N2—C12—C9 | −179.33 (13) | N2—C12—C9—C21 | 57.33 (17) |
C12—N2—C13—C14 | −161.12 (15) | N2—C12—C9—C11 | 179.05 (13) |
C12—N2—C13—C15 | 76.00 (17) | N2—C12—C9—C10 | −61.98 (17) |
C6—C1—C2—C3 | 0.5 (3) | C16—C15—C13—N2 | −142.22 (16) |
C2—C3—C4—C5 | −0.7 (3) | C20—C15—C13—N2 | 42.5 (2) |
C4—C3—C2—C1 | 0.9 (3) | C16—C15—C13—C14 | 96.1 (2) |
O1—C5—C4—C3 | 179.13 (19) | C20—C15—C13—C14 | −79.2 (2) |
C6—C5—C4—C3 | −0.8 (3) | C20—C15—C16—C17 | 1.7 (3) |
C5—C6—C1—C2 | −2.0 (3) | C13—C15—C16—C17 | −173.71 (18) |
C7—C6—C1—C2 | 175.56 (16) | C16—C15—C20—O2 | 179.33 (17) |
C1—C6—C5—O1 | −177.83 (16) | C13—C15—C20—O2 | −5.3 (3) |
C7—C6—C5—O1 | 4.7 (2) | C16—C15—C20—C19 | −1.5 (3) |
C1—C6—C5—C4 | 2.1 (3) | C13—C15—C20—C19 | 173.86 (16) |
C7—C6—C5—C4 | −175.45 (17) | C16—C17—C18—C19 | −0.7 (3) |
C1—C6—C7—N1 | 138.62 (16) | C18—C17—C16—C15 | −0.6 (3) |
C5—C6—C7—N1 | −43.9 (2) | C20—C19—C18—C17 | 0.9 (3) |
C1—C6—C7—C8 | −100.1 (2) | O2—C20—C19—C18 | 179.43 (18) |
C5—C6—C7—C8 | 77.3 (2) | C15—C20—C19—C18 | 0.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O2 | 0.85 (2) | 2.53 (2) | 3.254 (2) | 144.9 (15) |
O1—H1O···N1 | 0.82 | 1.92 | 2.648 (2) | 147 |
N2—H2N···O1i | 0.95 (2) | 2.49 (2) | 3.3833 (19) | 156.00 |
O2—H2O···N2 | 0.82 | 1.95 | 2.671 (2) | 147 |
Symmetry code: (i) −x+1, y+1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C21H30N2O2 |
Mr | 342.47 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 298 |
a, b, c (Å) | 11.4232 (3), 10.1303 (3), 18.4399 (4) |
β (°) | 107.753 (5) |
V (Å3) | 2032.26 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.2 × 0.13 × 0.1 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID-S |
Absorption correction | Multi-scan (Blessing, 1995) |
Tmin, Tmax | 0.986, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 57575, 6244, 3287 |
Rint | 0.063 |
(sin θ/λ)max (Å−1) | 0.722 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.207, 1.04 |
No. of reflections | 6244 |
No. of parameters | 241 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.19, −0.15 |
Computer programs: CrystalClear (Rigaku/MSC, 2005), CrystalClear, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O2 | 0.85 (2) | 2.53 (2) | 3.254 (2) | 144.9 (15) |
O1—H1O···N1 | 0.82 | 1.92 | 2.648 (2) | 147.00 |
N2—H2N···O1i | 0.95 (2) | 2.49 (2) | 3.3833 (19) | 156.00 |
O2—H2O···N2 | 0.82 | 1.95 | 2.671 (2) | 147.00 |
Symmetry code: (i) −x+1, y+1/2, −z+3/2. |
It has been reported by many studies that Schiff bases form mononuclear or dinuclear compounds with phenylboronic and boric acids (Burgess et al., 1999; Höpfl et al., 1998; Maciejewska et al., 1999; Mitra et al., 2006; Mitra et al., 2004). In these studies, the compounds of reduced forms of Schiff bases also exist (Mitra et al., 2006). It has been noted that tri- and tetracoordinated compounds are formed between reduced Schiff bases and organic esters of boric acid. In this study, an ONNO type Schiff base has reduced to phenol imine form with the usage of NaBH4 in MeOH media. In fact, it was aimed to prepare a new complex from reaction of Schiff base and phenylboronic acid, but Schiff base crystal which is suitable for X-ray analysis was obtained. When ligand is crystallized in the common solvents, the appropriate single crystals for X-ray analysis could not be obtained. It was concluded that first phenylboronic acid and ligand are formed an intermediate complex, which is affected the solubility of Schiff base. Hence it was inferred that this procedure could be a new recrystallization method for organic ligands. We report herein the crystal structure of the title compound, (I).
In the molecule of (I) (Fig. 1), the bond lengths and angles are generally within normal ranges (Allen et al., 1987). In the form of the Schiff base, C=N double bond is about 1.27–1.30 Å (Sanchez et al., 2004). After the reduction reaction of double bond, it was converted to mono bonds (C7—N1 [1.483 (2) Å] and C13—N2 [1.481 (2) Å]). The strong hydrogen bond between iminic nitrogen (in the form of Schiff base) and phenol group continued after reduction (Yalçın et al., 2001).
Rings A (C1—C6) and B (C15—C20) are, of course, planar and the dihedral angle between them is A/B = 89.65 (2)°.
In the crystal structure, intermolecular N—H···O and intramolecular O—H—N and N—H—O hydrogen bonds (Table 1) result in the formation of chains along the b axis (Fig. 2), in which they seem to be effective in the stabilization of the structure.