Two new complexes,
Imidazole and its derivatives have played a formative role in the development of coordination chemistry [
It is well established nowadays that the most prominent intermolecular interactions responsible for the supramolecular organization of metal complexes are hydrogen bonds and
Drawing of the ligand 1-methyl-4,5-diphenylimidazole.
In this study we present our results on the
Chemicals (reagent grade) were purchased from Merck and Alfa Aesar. All manipulations were performed under aerobic conditions using materials and solvents as received; water was distilled in-house. The ligand 1-methyl-4,5-diphenylimidazole (L) was synthesized as already described in a previous work [
This compound was synthesized by a solvothermal reaction of L (0.18 g, 0.75 mmol) and Zn(O2CPh)2·2H2O (0.10 g, 0.30 mmol) in MeOH (8 mL). The reaction mixture was loaded into a Teflon-lined stainless steel autoclave with inner volume of 20 mL, and then the sealed autoclave was heated under autogenous pressure at
A pale yellow solution of L (0.29 g, 1.25 mmol) in MeCN/CH2Cl2 (30 mL, 1 : 1 v/v) was treated with solid Ni(O2CPh)2·2H2O (0.17 g, 0.50 mmol). The resulting green slurry was stirred at ambient temperature for 20 min. The solution was filtered and the green filtrate was left undisturbed in a closed vial at room temperature. After 15 days, light-green crystals of
Selected single crystals of
Crystal data and refinement parameters for complexes
Empirical formula | C48H46N4O6Zn | C64H54N6O8Ni2 |
Formula weight (g mol−1) | 840.26 | 1152.55 |
Temperature | 100(2) | 100(2) |
Wavelength | 0.71073 | 0.71073 |
Crystal system | monoclinic | Monoclinic |
Space group | ||
13.8301(2) | 29.7994(16) | |
16.2359(2) | 10.4438(6) | |
18.6267(3) | 18.1018(11) | |
94.075(2) | 98.745(6) | |
4171.94(10) | 5568.1(6) | |
4 | 4 | |
Density (calculated) (g cm−3) | 1.338 | 1.375 |
Absorption coefficient (mm−1) | 0.644 | 0.739 |
1760 | 2400 | |
Crystal size (mm) | ||
Colour, habit | colorless, prism | light green, plate |
3.07 to 30.29 | 3.15 to 30.39 | |
Index ranges | ||
Reflections collected/unique ( | ||
Observed reflections [ | 7850 | 2906 |
Data/restraints/parameters | ||
Goodness-of-fit on | 0.962 | 0.805 |
Final | 0.0324, 0.0788 | 0.0392, 0.0591 |
Mean and max shift/error | 0.000 and 0.002 | 0.000 and 0.001 |
Largest diff. peak and hole (e Å−3) | 0.503 and |
CCDC-771769 and CCDC-771770 contain the crystallographic data for
The reactions that led to complexes
Two features of the reactions represented by (
The IR bands of L [
The molecular structures of complexes
Selected interatomic distances (Å), angles and torsion angles (
Compound | ||
---|---|---|
M | Zn | Ni |
M | 2.734 | |
M–N3A | 2.007 | 2.017(2) |
M–N3B | 2.065 | |
M–O1 | 1.947 | 2.015(2) |
M–O3 | 1.950 | 2.039(2) |
M–O2 | 2.008(2) | |
M–O4 | 2.026(2) | |
N3A–M–N3B | 96.6 | |
N3A–M–O1 | 123.4 | 91.9 |
N3A–M–O2 | 103.3 | |
N3A–M–O3 | 123.9 | 98.2 |
N3A–M–O4 | 96.7 | |
N3B–M–O1 | 103.0 | |
N3B–M–O3 | 97.2 | |
O1–M–O3 | 105.7(4) | 88.0 |
O1–M–O4 | 89.9 | |
O2–M–O3 | 90.7 | |
O2–M–O4 | 87.4 | |
C19–M–C26 | 112.46(4) | |
A2–A3* | 70.5 | 61.9 |
B2–B3* | 67.0 | |
C4A–C5A–C13A–C14A | −57.8(2) | −53.0(4) |
C4B–C5B–C13B–C14B | −56.8(2) | |
C5A–C4A–C7A–C12A | −46.6(2) | −40.5(4) |
C5B–C4B–C7B–C12B | −37.3(2) |
Symmetry codes: (i)
A partially labeled plot of complex
A partially labeled plot of the dinuclear complex
Complex
Geometrical details (Å,
Rings | Distance/Angle | |
---|---|---|
Distance between ring centroids | A1–B2 | 3.547 |
B1–A2 | 3.622 | |
Perpendicular distance between ring planes | A1–B2 | 3.437 |
B1–A2 | 3.363 | |
Centroid offset | A1–B2 | 0.876 |
B1–A2 | 1.346 | |
Dihedral angle between ring mean-planes | A1–B2 | 10.5 |
B1–A2 | 4.9 |
One of the methanol molecules (O5) in the lattice is involved in two strong intramolecular O–H
Hydrogen-bond geometries for
D–H | D–H | H | D | D–H |
---|---|---|---|---|
O6–H6 | 0.855(19) | 1.916(19) | 2.764(2) | 172(2) |
O5–H5 | 0.847(17) | 1.913(17) | 2.738(2) | 165(2) |
C8B–H8B | 0.93 | 2.50 | 3.282(2) | 142 |
C6B–H6B3 | 0.96 | 2.432 | 3.370(2) | 166 |
C33–H33B | 0.96 | 2.52 | 3.423(2) | 157 |
C8A–H8A | 0.93 | 2.30 | 3.151(3) | 152 |
C34–H34C | 0.96 | 2.50 | 3.371(4) | 151 |
Symmetry codes: (i)
View of the crystal packing of complex
The dinuclear paddle-wheel type complex
It should be mentioned that attempts were made to prepare metal(II)-benzoate complexes with the 1-methyl-4,5-diphenylimidazole ligand for the divalent metals Co, Ni, Cu, and Zn, varying the factors that could affect the self-assembly of supramolecular architectures (such as the solvents used, temperature, counter-ion, the ligand-to-metal ratio, method of preparation, etc.). However, our trials yielded only the present two crystalline materials. It seems that the capability of the benzoate group to adopt different ligation modes plays, at least in the present case, a role in the formation of different coordination structural types.
The use of 1-methyl-4,5-diphenylimidazole ligand (L) in reactions with Zn(O2CPh)2·2H2O and Ni(O2CPh)2·2H2O has yielded the mononuclear [Zn(O2CPh)2(L)2]·2MeOH complex (
This paper was supported by the Research Committee of the University of Patras, Greece (K. Caratheodory program, Grant no C.585 to Vassilios Nastopoulos).