RESUMO
The unit cell of the title compound, [Fe(C18H15N6O2)2]·2CH3OH·2CHCl3, consists of a charge-neutral complex mol-ecule, two methanol and two chloro-form mol-ecules. In the complex, the two tridentate 2-(5-(3,4-di-meth-oxy-phen-yl)-1,2,4-triazol-3-yl)-6-(pyrazol-1-yl)pyridine ligands coordinate to the central FeII ion through the N atoms of the pyrazole, pyridine and triazole groups, forming a pseudo-octa-hedral coordination sphere. Neighbouring tapered mol-ecules are linked through weak C-H(pz)â¯π(ph) inter-actions into one-dimensional chains, which are joined into two-dimensional layers through weak C-Hâ¯N/C/O inter-actions. Furthermore, the layers stack in a three-dimensional network linked by weak inter-layer C-Hâ¯π inter-actions of the meth-oxy and phenyl groups. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be Hâ¯H 32.0%, Hâ¯C/Câ¯H 26.3%, Hâ¯N/Nâ¯H 13.8%, and Hâ¯O/Oâ¯H 7.5%. The average Fe-N bond distance is 2.185â Å, indicating the high-spin state of the FeII ion. Energy framework analysis at the HF/3-21â G theory level was performed to qu-antify the inter-action energies in the crystal structure.
RESUMO
The reaction of cadmium bromide tetra-hydrate with 3-amino-pyrazole (3-apz) in ethano-lic solution leads to tautomerization of the ligand and the formation of crystals of the title compound, catena-poly[[di-bromido-cadmium(II)]-bis-(µ-3-amino-1H-pyrazole)-κ2 N 3:N 2;κ2 N 2:N 3], [CdBr2(C3H5N3)2]n or [CdBr2(3-apz)2]n. Its asymmetric unit consists of a half of a Cd2+ cation, a bromide anion and a 3-apz mol-ecule. The Cd2+ cations are coordinated by two bromide anions and two 3-apz ligands, generating trans-CdN4Br2 octa-hedra, which are linked into chains by pairs of the bridging ligands. In the crystal, the ligand mol-ecules and bromide anions of neighboring chains are linked through inter-chain hydrogen bonds into a two-dimensional network. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative qu-anti-tative contributions of the weak inter-molecular contacts.
RESUMO
The unit cell of the title compound, [FeII(C17H12BrN6O)2]·2MeOH, consists of a charge-neutral complex mol-ecule and two independent mol-ecules of methanol. In the complex mol-ecule, the two tridentate ligand mol-ecules 2-[5-(3-bromo-4-meth-oxy-phen-yl)-4H-1,2,4-triazol-3-yl]-6-(1H-pyrazol-1-yl)pyridine coordinate to the FeII ion through the N atoms of the pyrazole, pyridine and triazole groups, forming a pseudo-octa-hedral coordination sphere around the central ion. In the crystal, neighbouring asymmetric mol-ecules are linked through weak C-H(pz)â¯π(ph) inter-actions into chains, which are then linked into layers by weak C-Hâ¯N/C inter-actions. Finally, the layers stack into a three-dimensional network linked by weak inter-layer C-Hâ¯π inter-actions between the meth-oxy groups and the phenyl rings. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be Hâ¯H 34.2%, Hâ¯C/Câ¯H 25.2%, Hâ¯Br/Brâ¯H 13.2%, Hâ¯N/Nâ¯H 12.2% and Hâ¯O/Oâ¯H 4.0%. The average Fe-N bond distance is 1.949â Å, indicating the low-spin state of the FeII ion. Energy framework analysis at the HF/3-21â G theory level was performed to qu-antify the inter-action energies in the crystal structure.
RESUMO
As a result of the high symmetry of the Aea2 structure, the asymmetric unit of the title compound, [FeII(C18H15N6)2]·2MeOH, consists of half of a charge-neutral complex mol-ecule and a discrete methanol mol-ecule. The planar anionic tridentate ligand 2-[5-(3,4-di-methyl-phen-yl)-4H-1,2,4-triazol-3-ato]-6-(1H-pyrazol-1-yl)pyridine coordinates the FeII ion meridionally through the N atoms of the pyrazole, pyridine and triazole groups, forming a pseudo-octa-hedral coordination sphere of the central ion. The average Fe-N bond distance is 1.955â Å, indicating a low-spin state of the FeII ion. Neighbouring cone-shaped mol-ecules, nested into each other, are linked through double weak C-H(pz)â¯π(ph') inter-actions into mono-periodic columns, which are further linked through weak C-Hâ¯N'/C' inter-actions into di-periodic layers. No inter-actions shorter than the sum of the van der Waals radii of the neighbouring layers are observed. Energy framework analysis at the B3LYP/6-31â G(d,p) theory level, performed to qu-antify the inter-molecular inter-action energies, reproduces the weak inter-layer inter-actions in contrast to the strong inter-action within the layers. Inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, showing the relative contributions of the contacts to the crystal packing to be Hâ¯H 48.5%, Hâ¯C/Câ¯H 28.9%, Hâ¯N/Nâ¯H 16.2% and Câ¯C 2.4%.
RESUMO
The unit cell of the title compound, [FeII(NCS)2(C29H32N8O2)], consists of eight charge-neutral complex mol-ecules. In the complex mol-ecule, the tetra-dentate ligand N 1,N 3-bis-{[1-(4-meth-oxy-benz-yl)-1H-1,2,3-triazol-4-yl]methyl-ene}-2,2-di-methyl-propane-1,3-di-amine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole and aldimine groups. Two thio-cyanate anions, coordinated through their N atoms, complete the coordination sphere of the central Fe ion. In the crystal, neighbouring mol-ecules are linked through weak Câ¯C, Câ¯N and Câ¯S inter-actions into a one-dimensional chain running parallel to [010]. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be Hâ¯H (37.5%), Hâ¯C/Câ¯H (24.7%), Hâ¯S/Sâ¯H (15.7%) and Hâ¯N/Nâ¯H (11.7%). The average Fe-N bond distance is 2.167â Å, indicating the high-spin state of the FeII ion, which does not change upon cooling, as demonstrated by low-temperature magnetic susceptibility measurements.
RESUMO
The unit cell of the title compound, [FeII(NCS)2(C19H32N8)], consists of two charge-neutral complex mol-ecules. In the complex mol-ecule, the tetra-dentate ligand N 1 ,N 3-bis-[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methyl-ene]-2,2-di-methyl-propane-1,3-di-amine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole and aldimine groups. Two thio-cyanate anions, also coordinated through their N atoms, complete the coordination sphere of the central Fe ion. In the crystal, neighbouring mol-ecules are linked through weak C-Hâ¯C/S/N inter-actions into a three-dimensional network. The inter-mol-ecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be Hâ¯H 50.8%, Hâ¯C/Câ¯H 14.3%, Hâ¯S/Sâ¯H 20.5% and Hâ¯N/Nâ¯H 12.1%. The average Fe-N bond distance is 2.170â Å, indicating the high-spin state of the FeII ion, which does not change upon cooling, as demonstrated by low-temperature magnetic susceptibility measurements. DFT calculations of energy frameworks at the B3LYP/6-31â G(d,p) theory level were performed to account for the inter-actions involved in the crystal structure.
RESUMO
The unit cell of the title compound, [FeII(NCS)2(C25H28N8)], consists of two charge-neutral complex mol-ecules related by an inversion centre. In the complex mol-ecule, the tetra-dentate ligand N 1,N 3-bis-[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl-ene]-2,2-di-methyl-propane-1,3-di-amine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole moieties and aldimine groups. Two thio-cyanate anions, coordinating through their N atoms, complete the coordination sphere of the central ion. In the crystal, neighbouring mol-ecules are linked through weak C-Hâ¯π, C-Hâ¯S and C-Hâ¯N inter-actions into a two-dimensional network extending parallel to (011). The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be Hâ¯H (35.2%), Hâ¯C/Câ¯H (26.4%), Hâ¯S/Sâ¯H (19.3%) and Hâ¯N/Nâ¯H (13.9%).
RESUMO
In the asymmetric unit of the title coordination compound, {[Cu(CN)(C4H3OC2H5N2)][Cu(CN)]} n , there are two Cu atoms with different coordination environments. One CuI ion is coordinated in a triangular coordination geometry by the N atom of the 2-eth-oxy-pyrazine mol-ecule and by two bridging cyanide ligands, equally disordered over two sites exchanging C and N atoms, thus forming polymeric chains parallel to the c axis. The other Cu atom is connected to two bridging cyanide groups disordered over two sites with an occupancy of 0.5 for each C and N atom, and forming an almost linear polymeric chain parallel to the b axis. In the crystal, the two types of chain, which are orthogonal to each other, are connected by cuprophilic Cuâ¯Cu inter-actions [2.7958â (13)â Å], forming two-dimensional metal-organic coordination layers parallel to the bc plane. The coordination framework is further stabilized by weak long-range (electrostatic type) C-Hâ¯π inter-actions between cyano groups and 2-eth-oxy-pyrazine rings.
RESUMO
In the title polymeric complex, {[Fe(CN)2(C10H8N2)2(H2O)2][Au(CN)2]} n , the FeII ion, which is located on a twofold rotation axis, has a slightly distorted FeN4O2 octa-hedral geometry. It is coordinated by two phenyl-pyrazine mol-ecules, two water mol-ecules and two di-cyano-aurate anions, the Au atom also being located on a second twofold rotation axis. In the crystal, the coordinated di-cyano-aurate anions bridge the FeII ions to form polymeric chains propagating along the b-axis direction. In the crystal, the chains are linked by Owater-Hâ¯Ndi-cyano-aurate anions hydrogen bonds and aurophillic inter-actions [Auâ¯Au = 3.5661â (3)â Å], forming layers parallel to the bc plane. The layers are linked by offset π-π stacking inter-actions [inter-centroid distance = 3.643â (3)â Å], forming a supra-molecular metal-organic framework.
RESUMO
A mononuclear iron(II) complex [FeII(N4PyMe2)(OTf)](OTf)(1), supported by a new pentadentate ligand, bis(6-methylpyridin-2-yl)- N, N-bis((pyridin-2-yl)methyl)methanamine (N4PyMe2), has been isolated and characterized. Introduction of methyl groups in the 6-position of two pyridine rings makes the N4PyMe2 a weaker field ligand compared to the parent N4Py ligand. Complex 1 is high-spin in the solid state and converts to [FeII(N4PyMe2)(CH3CN)](OTf)2 (1a) in acetonitrile solution. The iron(II) complex in acetonitrile displays temperature-dependent spin-crossover behavior over a wide range of temperature. In its reaction with m-CPBA or oxone in acetonitrile at -10 °C, the iron(II) complex converts to an iron(IV)-oxo species, [FeIV(O)(N4PyMe2)]2+ (2). Complex 2 exhibits the Mössbauer parameters δ = 0.05 mm/s and Δ EQ = 0.62 mm/s, typical of N-ligated S = 1 iron(IV)-oxo species. The iron(IV)-oxo complex has a half-life of only 14 min at 25 °C and is reactive toward oxygen-atom-transfer and hydrogen-atom-transfer (HAT) reactions. Compared to the parent complex [FeIV(O)(N4Py)]2+, 2 is more reactive in oxidizing thioanisole and oxygenates the C-H bonds of aliphatic substrates including that of cyclohexane. The enhanced reactivity of 2 toward cyclohexane results from the involvement of the S = 2 transition state in the HAT pathway and a lower triplet-quintet splitting compared to [FeIV(O)(N4Py)]2+, as supported by DFT calculations. The second-order rate constants for HAT by 2 is well correlated with the C-H bond dissociation energies of aliphatic substrates. Surprisingly, the slope of this correlation is different from that of [FeIV(O)(N4Py)]2+, and 2 is more reactive only in the case of strong C-H bonds (>86 kcal/mol), but less reactive in the case of weaker C-H bonds. Using oxone as the oxidant, the iron(II) complex displays catalytic oxidations of substrates with low activity but with good selectivity.
RESUMO
In the title compound, C16H17NO4, the dihedral angle between benzene rings is 72.7â (2)°. The meth-oxy groups are rotated by 2.4â (2) and -4.9â (2) (benzil-idene moiety) and by 5.6â (3)° (aniline moiety) relative to the adjacent benzene ring. In the crystal, the mol-ecules are linked into chains along [101] through C-Hâ¯O and O-Hâ¯N hydrogen bonds.
RESUMO
The reaction of CoCl2 with succinic acid and isonicotinamide in basic solution produces the title complex [Co(C6H6N2O)2(H2O)4](C4H4O4). The cobalt(II) ion of the complex cation and the succinate anion are each located on an inversion centre. The CoII ion is octa-hedrally coordinated by four O atoms of water mol-ecules and two N atoms of isonicotinamide mol-ecules. The two ions are linked via Owater-Hâ¯Osuccinate hydrogen bonds, forming chains propagating along [001]. In the crystal, these hydrogen-bonded chains are linked into a three-dimensional framework by further O-Hâ¯O hydrogen bonds and N-Hâ¯O hydrogen bonds. The framework is reinforced by C-Hâ¯O hydrogen bonds. Hirshfeld surface analysis and two-dimensional fingerprint plots have been used to analyse the inter-molecular inter-actions present in the crystal.
RESUMO
The title compound, C25H20N2, (I), was synthesized from the condensation reaction of anthracene-9-carbaldehyde and tryptamine in dry ethanol. The indole ring system (r.m.s. deviation = 0.016â Å) makes a dihedral angle of 63.56â (8)° with the anthracene ring (r.m.s. deviation = 0.023â Å). There is a short intra-molecular C-Hâ¯N inter-action present, and a C-Hâ¯π inter-action involving the two ring systems. In the crystal, the indole H atom forms an inter-molecular N-Hâ¯π inter-action, linking mol-ecules to form chains along the b-axis direction. There are also C-Hâ¯π inter-actions present, involving the central and terminal rings of the anthracene unit, linking the chains to form an overall two-dimensional layered structure, with the layers parallel to the bc plane. The density functional theory (DFT) optimized structure, at the B3LYP/6-311â G(d,p) level, is compared with the experimentally determined mol-ecular structure in the solid state.
RESUMO
In the title compound, [Ni(C13H18NO3)2(C12H8N2)], the NiII cation shows a distorted octa-hedral coordination environment. It is formed by two N atoms from the phenanthroline ligand, as well as two N and two O atoms belonging to two 2-[(2-hy-droxy-benz-yl)amino]-4-methyl-penta-noate ligands. Complex mol-ecules are connected into layers propagating along the ab plane via hydrogen bonds formed by O atoms of carboxyl-ate and phenoxide groups, which are further connected into a three-dimensional motif.
RESUMO
Two new pentadentate {N5} donor ligands based on the N4Py (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) framework have been synthesized, viz. [N-(1-methyl-2-benzimidazolyl)methyl-N-(2-pyridyl)methyl-N-(bis-2-pyridyl methyl)amine] (L(1)) and [N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L(2)), where one or two pyridyl arms of N4Py have been replaced by corresponding (N-methyl)benzimidazolyl-containing arms. The complexes [Fe(II)(CH3CN)(L)](2+) (L = L(1) (1); L(2) (2)) were synthesized, and reaction of these ferrous complexes with iodosylbenzene led to the formation of the ferryl complexes [Fe(IV)(O)(L)](2+) (L = L(1) (3); L(2) (4)), which were characterized by UV-vis spectroscopy, high resolution mass spectrometry, and Mössbauer spectroscopy. Complexes 3 and 4 are relatively stable with half-lives at room temperature of 40 h (L = L(1)) and 2.5 h (L = L(2)). The redox potentials of 1 and 2, as well as the visible spectra of 3 and 4, indicate that the ligand field weakens as ligand pyridyl substituents are progressively substituted by (N-methyl)benzimidazolyl moieties. The reactivities of 3 and 4 in hydrogen-atom transfer (HAT) and oxygen-atom transfer (OAT) reactions show that both complexes exhibit enhanced reactivities when compared to the analogous N4Py complex ([Fe(IV)(O)(N4Py)](2+)), and that the normalized HAT rates increase by approximately 1 order of magnitude for each replacement of a pyridyl moiety; i.e., [Fe(IV)(O)(L(2))](2+) exhibits the highest rates. The second-order HAT rate constants can be directly related to the substrate C-H bond dissociation energies. Computational modeling of the HAT reactions indicates that the reaction proceeds via a high spin transition state.
Assuntos
Hidrogênio/química , Ferro/química , Compostos Organometálicos/química , Oxigênio/química , Eletroquímica , Ligantes , Modelos Moleculares , Conformação Molecular , Compostos Organometálicos/síntese química , Oxirredução , Piridinas/química , Sulfetos/químicaRESUMO
The title compound, [Ni(C7H6N2O3)(C12H8N2)2]·3.5H2O, crystallizes as a neutral mononuclear complex with 3.5 solvent water mol-ecules. One of the water mol-ecules lies on an inversion centre, so that its H atoms are disordered over two sites. The coordination environment of Ni(II) has a slightly distorted octa-hedral geometry, which is formed by one O and five N atoms belonging to the N,O-chelating pyrazol-1-ide-5-carboxyl-ate and two N,N'-chelating phenanthroline mol-ecules. In the crystal, O-Hâ¯O, N-Hâ¯O and O-Hâ¯N hydrogen bonds involving the solvent water mol-ecules and pyrazole-5-carboxyl-ate ligands form layers parallel to the ab plane. These layers are linked further via weak π-π inter-actions between two adjacent phenanthroline mol-ecules, with centroid-to-centroid distances in the range 3.886â (2)-4.018â (1)â Å, together with C-Hâ¯π contacts, forming a three-dimensional network.
RESUMO
In the title compound, [Cu(C7H6N2O3)(C6H8N2)(H2O)], the Cu(II) ion is in a distorted square-pyramidal N3O2 environment formed by two bidentate chelating ligands in the equatorial coordination sites and one water mol-ecule in the apical direction. In the crystal, O-Hâ¯O, N-Hâ¯O and O-Hâ¯N hydrogen bonds link the complex mol-ecules into a three-dimensional supra-molecular network.
RESUMO
In the title compound, C(8)H(11)N(3)O(2), the oxime and the acetyl groups adopt a transoid conformation, while the pyrazole H atom is localized in the proximity of the acetyl group and is cis with respect to the acetyl O atom. In the crystal, dimers are formed as the result of hydrogen-bonding inter-actions involving the pyrazole NH group of one mol-ecule and the carbonyl O atom of another. The dimers are associated into sheets via O-Hâ¯N hydrogen bonds involving the oxime hydroxyl and the unprotonated pyrazole N atom, generating a macrocyclic motif with six mol-ecules.
RESUMO
The title compound, [Cu(4)(C(7)H(6)N(2)O(3))(4)(H(2)O)(4)]·14H(2)O, a tetra-nuclear [2â ×â 2] grid-type complex with S4 symmetry, contains four Cu(II) atoms which are bridged by four pyrazole-carboxyl-ate ligand anions and are additionally bonded to a water molecule. Each Cu(II) atom is coordinated by two O atoms of the carboxyl-ate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carb-oxy-lic acid and one O atom of a water mol-ecule. The geometry at each Cu(II) atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O-Hâ¯O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.
RESUMO
The title compound, [Cu(2)(C(7)H(6)N(2)O(3))Cl(2)(C(5)H(5)N)(4)]·C(3)H(8)O, is a binuclear pyrazolate complex, in which the two Cu(II) atoms have different coordination numbers and are connected by a bridging Cl atom. One Cu(II) atom has a distorted square-pyramidal coordination environment formed by two pyridine N atoms, one bridging Cl atom and an N,O-chelating pyrazolate ligand. The other Cu(II) atom adopts an octa-hedral geometry defined by two pyridine N atoms at the axial positions, two Cl atoms and the coordinated pyrazolate ligand in the equatorial plane. An O-Hâ¯O hydrogen bond connects the complex mol-ecules and propan-2-ol solvent mol-ecules into pairs. These pairs form columns along the a axis.