Direct MP2 molecular dynamics studies of H atom reaction with CD4 and CH4

The mechanism and dynamics of the H + CD₄ → CD₃ + HD (I) and H + CH₄ → CH₃ + H₂ (II) reactions have been investigated by electronic structure methods. The minimum‐energy path and vibrational frequencies along the intrinsic reaction coordinate are calculated at MP2/cc‐pVDZ level. Energy distributions of the products are also obtained by the direct classical trajectory calculations at the MP2/ cc‐pVDZ level. It is found that most of the available energy appears as product translational energy, and very little of the available energy is partitioned into internal excitation of the HD (H₂) product for reaction I (II), which is in agreement with the experimental evidence. The results indicate that the experimental results could be reproduced by the direct MP2 molecular dynamics calculations. The rotational state distributions of the products show the HD (H₂) products are formed with lower rotational quantum numbers than the CD₃ (CH₃) products. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

The gas phase hydrogen‐bonded dimers of HOCl: A high‐level quantum chemical study

The O···H? O and Cl···H? O hydrogen bonding interactions were analyzed for HOCl dimers by using B3LYP, MP2, CCSD, and MP4(SDTQ) methods in conjunction with the various basis sets. Five isomers were found for the HOCl dimer. The ZPE and BSSE corrected binding energies were computed at the different levels of theory. At the optimized geometries obtained at CCSD/AUG‐cc‐pVDZ level, energies were re‐evaluated at MP4(SDTQ)/AUG‐cc‐pVTZ and CCSD(T)/cc‐pVTZ levels of theory. We found an average of ?20.9 and ?9.6 kJ/mol for the strength of the O···H and Cl···H hydrogen bonding interactions, respectively. Excitation and vertical ionization energies as well as rotational constants were computed at different levels of theory. The quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis were used to elucidate the nature of the interactions of HOCl dimers. The interaction energies were decomposed by Morokuma methodology. We have computed Δ_fH°(HOCl) and Δ_fH°(HOCl⁺) using the atomization reactions. The Δ_fH°₂₉₈(HOCl) values are ?17.85 and ?18.05 kcal/mol by using CBS‐Q and CBS‐QB3 extrapolation models, respectively, in good agreement with the results given in JANAF tables. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Darstellung,Ramanspektren und Kristallstrukturen von V2O3(SO4)2, K[VO(SO4)2] und NH4[VO(SO4)2]

Preparation, Raman Spectra, and Crystal Structures of V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] The oxo-sulfato-vanadates(V) V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] have been prepared as crystals suitable for X-ray structure determination. In all structures sulfate acts as an unidentate ligand only toward a single vanadium atom. The structure of V₂O₃(SO₄)₂ consists of a threedimensional network of pairs of cornershared VO₆ octahedra with one terminal oxygen atom each, and SO₄ tetrahedra. All oxygen atoms of the sulfate ions are coordinated. NH₄[VO(SO₄)₂] and K[VO(SO₄)₂] are isostructural. VO₆ octahedra with one terminal oxygen atom and pairs of sulfate tetrahedra form infinite chains by corner sharing. The chains are weakly interlinked to layers. The sulfate ions are distorted towards planar SO₃ molecules and single oxygen atoms attached to vanadium. This structural detail gives an explanation for the mechanism of the reversible reaction K[VO(SO₄)₂] ? K[VO₂(SO₄)] + SO₃ at 400°C. Raman spectra of the compounds have been recorded and interpreted with respect to their structures. Crystal data: V₂O₃(SO₄)₂, monoclinic, space group P2₁/a, a = 947.2(4), b = 891.3(3), c? 989.1(4) pm, β = 104.56(3)°, Z = 4, 878 unique data, R(R_w) = 0.039(0,033); K[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(2), b = 869.6(9), c = 1 627(1)pm, Z = 4, 642 unique data, R(R_w) = 0,11(0,10); NH₄[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(1), b = 870.0(2), c = 1 676.7(4)pm, Z = 4, 768 unique data, R(R_w) = 0.088(0.083).     

Crystal Structures of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O

Reactions of 1,10‐phenanthroline monohydrate, Na₂C₄H₄O₄ · 6 H₂O and MnSO₄ · H₂O in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] · 2 H₂O ( 1 ) and [Mn(phen)₂(H₂O)₂][Mn(phen)₂(C₄H₄O₄)](C₄H₄O₄) · 7 H₂O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) ų, Z = 1) consists of the dinuclear [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] molecules and hydrogen bonded H₂O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H₂O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) ų, Z = 2) is composed of the [Mn(phen)₂(H₂O)₂]²⁺ cations, [Mn(phen)₂(C₄H₄O₄)] complex molecules, (C₄H₄O₄)^2– anions, and H₂O molecules. The (C₄H₄O₄)^2– anions and H₂O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.     

LiLa2F3(SO4)2 und LiEr2F3(SO4)2: Fluoridsulfate der Selten‐Erd‐Elemente mit Lithium

LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂: Fluoride‐Sulfates of the Rare‐Earth Elements with Lithium The reaction of LiF with the anhydrous sulfates M₂(SO₄)₃ (M = La, Er) in sealed gold ampoules yields single crystals of the pseudo quaternary compounds LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂. According to X‐ray single crystal investigations, LiLa₂F₃(SO₄)₂ crystallizes with the monoclinic (I2/a, Z = 4, a = 828.3(2), b = 694.7(1), c = 1420.9(3) pm, β = 95.30(2)°, R_all = 0.0214) and LiEr₂F₃(SO₄)₂ with the orthorhombic crystal system (Pbcn, a = 1479.1(2), b = 633.6(1), c = 813.7(1) pm, R_all = 0.0229). A common feature of both structures is a dimeric unit of metal atoms connected via three fluoride ions. This leads to relatively short metal‐metal distances (La³⁺–La³⁺: 389 pm, Er³⁺–Er³⁺: 355 pm). In LiLa₂F₃(SO₄)₂, Li⁺ is surrounded by four oxygen atoms of four sulfate groups and one fluoride ion in form of a trigonal bipyramid, in LiEr₂F₃(SO₄)₂ two further fluoride ligands are attached.     

Synthese und Kristallstruktur von NaPr2F3(SO4)2

Synthesis and Crystal Strucure of NaPr₂F₃(SO₄)₂ Light green single crystals of NaPr₂F₃(SO₄)₂ have been obtained by the reaction of Pr₂(SO₄)₃ and NaF in sealed gold ampoules at 1050 °C. In the crystal structure (monoclinic, I2/a, Z = 4, a = 822.3(1), b = 692.12(7), c = 1419.9(2) pm, β = 95.88(2)°) Pr³⁺ is coordinated by four F^– ions and six oxygen atoms which belong to five SO₄^– ions. Thus, one of the latter acts as a bidentate ligand. The [PrO₆F₄] units are connected via three common fluoride ions to pairs with a Pr–Pr distance of 386 pm. Na⁺ is sevenfold coordinated by three fluorine and four oxygen atoms.     

MPI/OpenMP hybrid parallel algorithm for resolution of identity second‐order Møller–Plesset perturbation calculation of analytical energy gradient for massively parallel multicore supercomputers

A massively parallel algorithm of the analytical energy gradient calculations based the resolution of identity Møller–Plesset perturbation (RI‐MP2) method from the restricted Hartree–Fock reference is presented for geometry optimization calculations and one‐electron property calculations of large molecules. This algorithm is designed for massively parallel computation on multicore supercomputers applying the Message Passing Interface (MPI) and Open Multi‐Processing (OpenMP) hybrid parallel programming model. In this algorithm, the two‐dimensional hierarchical MP2 parallelization scheme is applied using a huge number of MPI processes (more than 1000 MPI processes) for acceleration of the computationally demanding O (N ⁵) step such as calculations of occupied–occupied and virtual–virtual blocks of MP2 one‐particle density matrix and MP2 two‐particle density matrices. The new parallel algorithm performance is assessed using test calculations of several large molecules such as buckycatcher C₆₀@C₆₀H₂₈ (144 atoms, 1820 atomic orbitals (AOs) for def2‐SVP basis set, and 3888 AOs for def2‐TZVP), nanographene dimer (C₉₆H₂₄)₂ (240 atoms, 2928 AOs for def2‐SVP, and 6432 AOs for cc‐pVTZ), and trp‐cage protein 1L2Y (304 atoms and 2906 AOs for def2‐SVP) using up to 32,768 nodes and 262,144 central processing unit (CPU) cores of the K computer. The results of geometry optimization calculations of trp‐cage protein 1L2Y at the RI‐MP2/def2‐SVP level using the 3072 nodes and 24,576 cores of the K computer are presented and discussed to assess the efficiency of the proposed algorithm. © 2017 Wiley Periodicals, Inc.     

Ein neues Lithiumhydrogensulfat,Li2(HSO4)2(H2SO4) – Synthese und Kristallstruktur

A New Lithium Hydrogen Sulfate, Li₂(HSO₄)₂(H₂SO₄) – Synthesis and Crystal Structure The title compound crystallizes in good shaped single crystals from the system lithium sulfate/sulfuric acid in the orthorhombic space group Pccn, unit cell parameters a = 17.645(4), b = 5.378(1), c = 10.667(3) Å. V = 1 012.2 ų, Z = 4, D_x = 2.009 g cm^?3. There are two types of SO₄ tetrahedra, SO₃(OH) and SO₂(OH)₂, connected via hydrogen bonds forming layers parallel to the xy-plane. The layers are linked by Li atoms, which are tetrahedral coordinated by O atoms coming two by two from neighboured layers.     

Uncatalyzed peptide bond formation between two double amino acid molecules in the gas phase

The gas phase mechanism for peptide bond formation between two double amino acid (DAA) molecules ((NH₂)₂C(COOH)₂) is investigated in the absence of any catalysts. Two different paths, concerted and stepwise, each leading to both cis and trans DAA‐DAA dipeptide products (four mechanisms total) are examined on the basis of theoretical calculations carried out at the CCSD(T)/aug‐cc‐pVDZ//MP2/aug‐cc‐pVDZ level. The investigation indicates that the concerted mechanism leading to the trans configuration of the peptide bond in the DAA‐DAA dipeptide product is thermodynamically favored by about 5 kcal mol^?1 and requires slightly less energy than the remaining pathways considered. Moreover, the peptide bond formation process between two DAA molecules in the gas phase resembles the analogous reactions between two natural amino acids.     

Synthesis and Characterization of the Trisulfate Pb[S3O10] and Theoretical Analysis of H2S3O10

The reaction of (NH₄)₂PbCl₆ and fuming sulfuric acid (65 % SO₃) in a sealed glass tube at 250 °C led to colorless single crystals of Pb[S₃O₁₀] (orthorhombic, Pbcn, Z = 4, a = 10.9908(4), b = 8.5549(3), c = 8.0130(3) Å, V = 753.42(5) ų). The compound shows a three‐dimensional linkage of the tenfold oxygen coordinated Pb²⁺ ions and exhibits the unusual trisulfate anion, [S₃O₁₀]^2–, that consists of three vertex connected [SO₄] tetrahedra. The distances S–O within the S–O–S bridges of the anion are remarkable asymmetric with distances of 155 and 169 pm, respectively. This structural feature is well reproduced by calculations on a PBE0/cc‐pVTZ and a MP2/cc‐pVTZ level of theory. Similar calculations allow also for an inspection of the yet unknown corresponding acid, H₂S₃O₁₀. Also for this acid non‐symmetric S–O–S bridges are predicted. The thermal behavior of Pb[S₃O₁₀] is characterized by the loss of two equivalents of SO₃ at low temperature and the decomposition of intermediate Pb[SO₄] at higher temperature.     

A new parallel algorithm of MP2 energy calculations

A new parallel algorithm has been developed for second‐order Møller–Plesset perturbation theory (MP2) energy calculations. Its main projected applications are for large molecules, for instance, for the calculation of dispersion interaction. Tests on a moderate number of processors (2–16) show that the program has high CPU and parallel efficiency. Timings are presented for two relatively large molecules, taxol (C₄₇H₅₁NO₁₄) and luciferin (C₁₁H₈N₂O₃S₂), the former with the 6‐31G* and 6‐311G** basis sets (1032 and 1484 basis functions, 164 correlated orbitals), and the latter with the aug‐cc‐pVDZ and aug‐cc‐pVTZ basis sets (530 and 1198 basis functions, 46 correlated orbitals). An MP2 energy calculation on C₁₃₀H₁₀ (1970 basis functions, 265 correlated orbitals) completed in less than 2 h on 128 processors. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 407–413, 2006     

New Structure Type among Octahydrated Rare‐Earth Sulfates, β‐Ce2(SO4)3·8H2O,and a new Ce2(SO4)3·4H2O Polymorph

Syntheses, crystal structures and thermal behavior of two new hydrated cerium(III) sulfates are reported, Ce₂(SO₄)₃·4H₂O ( I ) and β‐Ce₂(SO₄)₃·8H₂O ( II ), both forming three‐dimensional networks. Compound I crystallizes in the space group P2₁/n. There are two non‐equivalent cerium atoms in the structure of I , one nine‐ and one ten‐fold coordinated to oxygen atoms. The cerium polyhedra are edge sharing, forming helically propagating chains, held together by sulfate groups. The structure is compact, all the sulfate groups are edge‐sharing with cerium polyhedra and one third of the oxygen atoms, belonging to sulfate groups, are in the S–Oμ₃–Ce₂ bonding mode. Compound II constitutes a new structure type among the octahydrated rare‐earth sulfates which belongs to the space group Pn. Each cerium atom is in contact with nine oxygen atoms, these belong to four water molecules, three corner sharing and one edge sharing sulfate groups. The crystal structure is built up by layers of [Ce(H₂O)₄(SO₄)]_nⁿ⁺ held together by doubly edge sharing sulfate groups. The dehydration of II is a three step process, forming Ce₂(SO₄)₃·5H₂O, Ce₂(SO₄)₃·4H₂O and Ce₂(SO₄)₃, respectively. During the oxidative decomposition of the anhydrous form, Ce₂(SO₄)₃, into the final product CeO₂, small amount of CeO(SO₄) as an intermediate species was detected.     

Solvent effect of aqueous media on properties of glycine: Significance of specific and bulk solvent effects,and geometry optimization in aqueous media

Geometries of the normal (N) and zwitterionic (Z) forms of glycine (gly) and their complexes gly.(H₂O)_n, n = 0–2, were fully optimized in gas phase and aqueous media, and transition states located between the corresponding N and Z forms. The geometry was also optimized and vibrational spectra calculated for the gly.(H₂O)₃ complex of Z glycine. Density functional theory at the B3LYP/AUG‐cc‐pVDZ level was employed for the geometry optimization calculations in gas phase and aqueous media while single point energy calculations were performed at the MP2/AUG‐cc‐pVDZ level in each case. Solvation in bulk water was treated using the polarizable continuum model (PCM). Zero‐point energy correction to total energy and thermal energy correction to enthalpy were obtained at the B3LYP/AUG‐cc‐pVDZ level of theory in both gas phase and bulk aqueous media and these corrections were also considered to be valid for the corresponding single point energy calculations performed at the MP2/AUG‐cc‐pVDZ level of theory. When geometries of the complexes of glycine with water molecules are optimized in aqueous media, the calculated properties are found to be appreciably modified with respect to those obtained by gas phase geometry optimization followed by solvation in aqueous media. For several vibrational frequencies, the agreement between the calculated and experimentally observed results is improved appreciably when both the specific and bulk solvent effects are considered in combination with full geometry optimization in aqueous media. For certain vibrational frequencies, mode assignments have also been modified. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Halogen bonding between substituted chlorobenzene and trimethylamine: Decisive role of σ–hole and C?Cl bond breaking energy

Theoretical studies have been carried out on the halogen bonding interaction between para substituted chlorobenzene (Y C₆H₄Cl, Y = H, NH₂, CH₃, F, CN, NO₂) and N(CH₃)₃ using ab initio MP2/aug‐cc‐pVDZ and DFT based wB97XD/6‐311++G(d,p) methods. The positive electrostatic potential (V_S,max) on the Cl atom and the heterolytic bond breaking enthalpy of the C Cl bond have been calculated and their role on halogen bonding is discussed. The heterolytic bond breaking enthalpy of the C Cl bond is proposed as a measure of the strength of the σ‐hole on Cl atom. The binding strength of the complexes ranging between −6.13 kJ mol⁻¹ and −9.29 kJ mol⁻¹ are linearly related to the V_S,max of the Cl atom and the bond breaking enthalpy of the C Cl bond. In addition, energy decomposition analysis was performed on the halogen bonded complexes via symmetry adapted perturbation theory (SAPT) to predict the dominant energy component and the nature of the N···Cl interaction.     

Die Kristallstrukturen der Diquecksilber(I)-Salze von Aminobenzolsulfonsäuren

Crystal Structures of Dimercuri (I) Salts of p- and m-Sulfanilic Acids The crystal structures of the compounds Hg₂(p-H₂N–C₆H₄–SO₃)₂ ( 1 ), Hg₂(m-H₂N–C₆H₄–SO₃)₂ ( 2 ), and Hg₂(m-H₂N–C₆H₄–SO₃)₂ · 2H₂O ( 3 ) contain leaf-structures ( 1 and 3 ) or chain-structures ( 2 ), with nearly linear groups N–Hg–Hg–N, Hg–O-contacts and hydrogen-bridging bonds. The smaller density of 3 compared with 1 –caused by the steric hindrance through the ligand – declared the incorporation of water for raising the stabilising interaction in the crystals. The compound 3 is the kinetic controlled, the compound 2 the thermodynamic controlled product.     

Synthesis,structure, and properties of M<Subscript>3</Subscript>VO<Subscript>2</Subscript>(SO<Subscript>4</Subscript>)<Subscript>2</Subscript> (M = Rb,Cs)

Vanadium(V) complexes of general composition M₃VO₂(SO₄)₂ (M = Rb, Cs) were synthesized by a solid-state route. The individuality of the synthesized compounds was proved by X-ray and neutron diffraction, vibrational spectroscopy, and microscopic analysis. The X-ray diffraction patterns of M₃VO₂(SO₄)₂ were indexed to fit the monoclinic system (space group P2/c, Z = 4) with the following unit cell parameters: a = 11.6487(2) Å, b = 8.4469(2) Å, c = 12.1110(2) Å, β = 109.483(1)°, V = 1123.43 ų (Rb); a = 12.0546(3) Å b = 8.7706(2) Å, c = 12.6496(3) Å, β = 109.843(2)°, V = 1257.99 ų (Cs). In the crystal structure of M₃VO₂(SO₄)₂, [VO₂(SO₄)₂]^3? complex anions can be discerned in which the vanadium atom is surrounded by five oxygen atoms: two oxygen atoms form short terminal V–O bonds, and three oxygen atoms are from the two sulfato groups, one of which acts as a monodentate ligand and the other acts as a bidentate chelating ligand.     

Topologisch und elektronisch bemerkenswerte „reduzierte”︁ Cluster des Typs [V18O42(X)]n− (X = SO4, VO4) mit Td-Symmetrie und davon abgeleitete Cluster [V(18–p)As2pO42(X)]m− (X = SO3, SO4, H2O; p = 3, 4)

Reduced Clusters with Remarkable Topological and Electronic Properties of the Type of [V₁₈O₄₂(X)]^n? (X = SO₄, VO₄) with T_d-Symmetry and Related Clusters [V_(18—p)As_2pO₄₂(X)]^m? (X = SO₃, SO₄, H₂O; p = 3, 4) The novel cluster-compounds Na₆[V₁₈O₄₂H₉(VO₄)] · 21 H₂O, (NH₄)₈[V₁₈O₄₂(SO₄)] · 25 H₂O, K₆[V₁₅As₆O₄₂(H₂O)] · 8 H₂O, (NH₄)₆[V₁₄As₈O₄₂(SO₃)], (NH₄)₆[V₁₄As₈O₄₂(SO₄)] and [N(CH3)₃]₄[₄V₁₄As₈0₄₂(H₂0)] were prepared and characterized by IR- and UV/Vis/NIR-spectroscopy, magnetic measurements and complete crystal structure analysis. For structural data see Inhaltsübersicht. Topological relations to the rhombicuboctahedron spanned by 24 0-atoms of the genuine hypothetical a-Keggin ion, at which the square planes are capped by V?O or As₂O groups, are discussed. Of particular interest are the ?extended”? Keggin ions [V₁₈O₄₂(X)]ⁿ- (X = SO₄ VO₄), (formaly derived from the hypothetical genuine a-Keggin ion by addition of six V?O groups) which have quite different electron populations in spite of the same structure of their cluster shells.     

Highly accurate benchmark calculations of the interaction energies in the complexes C6H6···C6X6 (X = F,Cl, Br,and I)

Different from the case of the benzene dimer, the differences between the interaction energies are always less than 0.50 kcal/mol for face‐to‐face eclipsed, face‐to‐face staggered, and parallel‐displaced configurations of all investigated complexes C₆H₆···C₆X₆ (X = F, Cl, Br, and I). Hence, it is a great challenge for quantum chemists to accurately calculate the interaction energies for the three configurations of the complexes C₆H₆···C₆X₆. This work demonstrates that results obtained with the PBE0 density functional combined with the D3 dispersion correction (PBE0‐D3) and the basis set def2‐TZVPP are in excellent agreement with the estimates of the coupled‐cluster singles, doubles, and perturbative triples [CCSD(T)] complete basis set (CBS) limit. The other finding in this study is that, in comparison with the gold‐standard CCSD(T)/CBS benchmark, the spin‐component scaled (SCS) zeroth‐order symmetry‐adapted perturbation theory (SAPT0), when paired with the basis set aug‐cc‐pVDZ, performs also very well, and its performance is even better than that of the PBE0‐D3/def2‐TZVPP method or the conventional SAPT/aug‐cc‐pVQZ method. The findings of this study are very significant because both PBE0‐D3/def2‐TZVPP and SCS‐SAPT0/aug‐cc‐pVDZ can deal with the systems with more than 200 atoms.     

A theoretical analysis of substituted aromatic compounds

The substituents ? CH₃, ? F, ? NO₂, ? OCH₃, and ? CH₂?CH₂ were placed at the ortho, meta, and para positions on the aromatic molecules aniline, benzaldehdye, nitrobenzene, and phenol. MMFF94, AM1, B3LYP, M06, M06‐2X, ωB97X, ωB97X‐d, and RI‐MP2 using cc‐pVDZ and cc‐pVTZ and CCSD(T) with cc‐pVDZ basis sets were used to calculate the geometries and energies of all regiomers of the molecules. Relative energies of the ortho and meta regiomers relative to the para regiomers were calculated and compared to the CCSD(T) values. A good basis set correlation between cc‐pVDZ and cc‐pVTZ was observed in RI‐MP2. Overall, RI‐MP2 gave the best correlation with the CCSD(T) results. All of the hybrid functionals showed similar accuracy and could effectively describe the intramolecular hydrogen‐bonding interactions of these compounds. The methoxy group at the para position in methoxyaniline, methoxyphenol, methoxynitrobenzene, and methoxybenzaldehyde was rotated around the phenyl‐O bond. HF, along with the cc‐pVDZ basis with the other methods, generated inaccurate energy profiles for p‐methoxyphenol. For the density functional theory methods, it was necessary to use improved grids to get smooth curves. © 2013 Wiley Periodicals, Inc.     

Amine‐Templated One‐Dimensional Metal Sulfates Including a Mixed‐Valent Fe Compound with a Half‐Kagome Structure

Organically templated metal sulfates are relatively new. Six amine‐templated transition‐metal sulfates with different types of chain structures, including a novel iron sulfate with a chain structure corresponding to one half of the kagome structure, were synthesized by hydro/solvothermal methods. Amongst the one‐dimensional metal sulfates, [C₁₀N₂H₁₀][Zn(SO₄)Cl₂] ( 1 ) is the simplest, being formed by corner‐linked ZnO₂Cl₂ and SO₄ tetrahedra. [C₆N₂H₁₈][Mn(SO₄)₂(H₂O)₂] ( 2 ) and [C₂N₂H₁₀][Ni(SO₄)₂(H₂O)₂] ( 3 ) have ladder structures comprising four‐membered rings formed by SO₄ tetrahedra and metal–oxygen octahedra, just as in the mineral kröhnkite. [C₄N₂H₁₂][V^III(OH)(SO₄)₂]?H₂O ( 4 ) and [C₄N₂H₁₂][VF₃(SO₄)] ( 5 ) exhibit chain topologies of the minerals tancoite and butlerite, respectively. The structure of [C₄N₂H₁₂][H₃O][Fe^IIIFe^II F₆(SO₄)] ( 6 ) is noteworthy in that it corresponds to half of the hexagonal kagome structure. It exhibits ferrimagnetic properties at low temperatures and the absence of frustration, unlike the mixed‐valent iron sulfate with the full kagome structure.