Trigonal Ligands Research Articles

Structures and catalytic oxidative coupling reaction of four Co-MOFs modified with R-isophthalic acid (RH, OH and COOH) and trigonal ligands

Four Co-MOFs involving R-isophthalic acid and n-TBT ligands have been synthesized and structurally characterized. Co-MOF-4 exhibits excellent catalytic performance for the oxidative coupling reaction under solvent-free condition and an air atmosphere.

A Dual‐Ligand Porous Coordination Polymer Chemiresistor with Modulated Conductivity and Porosity

AbstractSingle‐ligand‐based electronically conductive porous coordination polymers/metal–organic frameworks (EC‐PCPs/MOFs) fail to meet the requirements of numerous electronic applications owing to their limited tunability in terms of both conductivity and topology. In this study, a new 2D π‐conjugated EC‐MOF containing copper units with mixed trigonal ligands was developed: Cu3(HHTP)(THQ) (HHTP=2,3,6,7,10,11‐hexahydrotriphenylene, THQ=tetrahydroxy‐1,4‐quinone). The modulated conductivity (σ≈2.53×10−5 S cm−1 with an activation energy of 0.30 eV) and high porosity (ca. 441.2 m2 g−1) of the Cu3(HHTP)(THQ) semiconductive nanowires provided an appropriate resistance baseline and highly accessible areas for the development of an excellent chemiresistive gas sensor.

A Dual-Ligand Porous Coordination Polymer Chemiresistor with Modulated Conductivity and Porosity.

Single-ligand-based electronically conductive porous coordination polymers/metal-organic frameworks (EC-PCPs/MOFs) fail to meet the requirements of numerous electronic applications owing to their limited tunability in terms of both conductivity and topology. In this study, a new 2D π-conjugated EC-MOF containing copper units with mixed trigonal ligands was developed: Cu3 (HHTP)(THQ) (HHTP=2,3,6,7,10,11-hexahydrotriphenylene, THQ=tetrahydroxy-1,4-quinone). The modulated conductivity (σ≈2.53×10-5 S cm-1 with an activation energy of 0.30 eV) and high porosity (ca. 441.2 m2 g-1 ) of the Cu3 (HHTP)(THQ) semiconductive nanowires provided an appropriate resistance baseline and highly accessible areas for the development of an excellent chemiresistive gas sensor.

A Ni3(OH)(COO)6 −based MOF from C3 symmetric ligands: Structure and heterogeneous catalytic activities in one-pot synthesis of imine

A new Ni(II)-metal organic framework was self-assembled by the reaction of tripodal benzene-1,3,5-tribenzoic acid (H 3 BTB), 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) and Ni II salts under solvothermal conditions. {[Ni 3 (OH)(BTB) 2 (TPT)[NH(CH 3 ) 2 ]} n •2nH 2 O ( MOF1 ) exhibited two-fold interpenetrated three-dimensional (3D) framework, which was constructed from the Ni 3 (OH)(COO) 6 trinuclear unit, connected by the mixed H 3 BTB and TPT ligands. In 1 , the trinuclear Ni 3 (OH)(COO) 6 units were firstly linked into 3D network by tripodal BTB 3− ligands, which were further accommodated with another size-matched trigonal TPT ligands, and novel (3,8)-connected 3D net was created. The catalytic measurements showed that compound 1 was a good heterogeneous catalyst for the one-pot synthesis of imines from benzyl alcohols and aniline under solvent-free condition, and the catalyst could be recycled without losing its structural integrity and catalytic activity. The Ni II - coordination polymer constructed from two size-matched C 3 symmetric ligands with novel two-fold interpenetrated (3,8)-connected 3D net exhibits catalytic activities in one-pot synthesis of imine under solvent-free condition. • Two trigonal ligands with C 3 symmetry are size-matching in MOF 1. • MOF 1 was constructed from the Ni 3 (OH)(COO) 6 trinuclear unit, and exhibits novel (3,8)-connected two-fold interpenetrated 3D net. • MOF 1 is a good heterogeneous catalyst for the one-pot synthesis of imines under solvent-free condition.

Coordination Compounds of Lanthanides with Hydrazones of 3-Methyl-1-Phenyl-4-Formylpyrazole-5-One and 1,3,5-Benzenetricarboxylic acid

We describe the results of the X-ray diffraction study of a dysprosium(III) complex with trihydrazone of 3-methyl-1-phenyl-4-formylpyrazole-5-one and 1,3,5-benzenetricarboxylic acid, as well as a heteroligand gadolinium(III) complex with tri- and dihydrazone of 3-methyl-1-phenyl-4-formylpyrazole-5-one and 1,3,5-benzenetricarboxylic acid (H3L and H3L1 respectively). It is determined that the homoligand complex of dysprosium has a M4L4 composition and a pseudotetrahedral structure in which metal ions occupy vertices of a trigonal pyramid and trinucleating ligands are located on its sides. The heteroligand gadolinium complex Gd3(L)(HL1)3 has a trigonal structure. Metal ions at the triangle vertices are linked by a trinucleating ligand located above the triangle plane, and three binucleating ligands link the central atoms in pairs. The geometry of dysprosium and gadolinium coordination polyhedra correspond to a three-capped trigonal prism.

An unusual polythreaded coordination network self-assembled from 2D motifs with two distinct lateral arms

Self-assembly of the trigonal 1,3,5-benzenetricarboxylate (H3btc) and copper salt in the presence of large trigonal N-containing ligand yields a fascinating entangled network, [Cu(Hbtc)(Htpba)]·1.5H2O (1) (Htpba=4-([4,2′:6′,4″-terpyridin]-4′-yl) benzoic acid). Compound 1 exhibits a novel (2D→3D) polythreaded network that is first assembled from 2D layers with two types of lateral arms. By inspection of the structure of 1, it is believed that the trigonal ligands with uncoordinated groups acting as dangling lateral arms play an important role in the formation of polythreaded network. The magnetic properties of compound 1 have been studied in the temperature range 2–300K.

Unusual three-dimensional coordination networks with [WS4Cu6] cluster nodes and α-C3N4topology

Two new 3D frameworks [(WS4Cu6Br4)(timp)8/3(H2O)40/3]n (1) and [(WS4Cu6Br4) (timtz)8/3(H2O)40/3]n (2), containing heptanuclear cluster blocks (one W atom and six Cu atoms) bridged by trigonal ligands timp or timtz (timp = 1-(3,5-di (1H-imidazol-1-yl)phenyl)-1H-imidazole; timtz = 2,4,6-tri(1H-imidazol-1-yl)-1,3,5-triazine), were successfully synthesized. Both compounds were characterized by single-crystal X-ray diffraction, elemental analysis, XRD, IR, TGA. X-ray determination shows that 1 and 2 can be topologically represented as (3,4)-connected networks with α-C3N4 (or ctn) topology where [WS4Cu6] act as the 4-connecting nodes, and the timp or timtz ligands bridge in pairs that act as the three-connecting nodes. Both compounds have the high symmetry of space group I-43d, which is the maximum symmetry for this net topology. The luminescent spectra and N2 absorption behaviors for 1 and 2 have also been investigated.

Spontaneous assembly of a hinged coordination network

THE field of supramolecular chemistry has advanced to a stage at which it is possible to select building blocks that will self-assemble into structures with specific network topologies1–3. This makes possible the rational design and synthesis of molecular solids with potentially interesting properties. Here we report the construction of open, hinged networks from molecular building blocks. This class of materials has been predicted to exhibit unusual mechanical properties, including auxetic behaviour (negative Poisson's ratio) and negative coefficients of thermal expansion4–6. Our approach relies on the notion that rigid organic molecules of high symmetry will adopt one of only a few possible structures when linked via hydrogen bonds or coordination to metals7–9. We use trigonal lig-ands to make networks joined at the vertices by metal ions; the resulting networks are homeotypic10 with the honeycomb-like A1B2 and the hinge-like ThSi2 phases. The hinge-like network has channels of inner diameter 15 A, within which included molecules can be exchanged while the framework remains intact. We have not yet determined whether this material is auxetic.

The 2.1 .ANG. resolution structure of iron superoxide dismutase from Pseudomonas ovalis

The 2.1-A resolution crystal structure of native uncomplexed iron superoxide dismutase (EC 1.15.1.1) from Pseudomonas ovalis was solved and refined to a final R factor of 24%. The dimeric structure contains one catalytic iron center per monomer with an asymmetric trigonal-bipyramidal coordination of protein ligands to the metal. Each monomer contains two domains, with the trigonal ligands (histidines 74 and 160; aspartate 156) contributed by the large domain and stabilized by an extended hydrogen-bonded network, including residues from opposing monomers. The axial ligand (histidine 26) is found on the small domain and does not participate extensively in the stabilizing H-bond network. The open axial coordination position of the iron is devoid of bound water molecules or anions. The metal is located 0.5 A out of the plane of the trigonal ligands toward histidine 26, providing a slightly skewed coordination away from the iron binding site. The molecule contains a glutamine residue in the active site which is conserved between all iron enzymes sequenced to data but which is conserved among all manganese SODs at a separate position in the sequence. This residue shows the same structural interactions in both cases, implying that iron and manganese SODs are second-site revertants of one another.

Molecular vibrations of complex with trigonal ligands

Molecular vibrations of complex with trigonal ligands

ChemInform Abstract: MOLECULAR VIBRATIONS OF A COMPLEX WITH TRIGONAL LIGANDS. PART XI. NORMAL COORDINATE ANALYSIS OF TETRAAMMINEPLATINUM(2+) ION

Chemischer InformationsdienstVolume 10, Issue 44 Physical Inorganic Chemistry ChemInform Abstract: MOLECULAR VIBRATIONS OF A COMPLEX WITH TRIGONAL LIGANDS. PART XI. NORMAL COORDINATE ANALYSIS OF TETRAAMMINEPLATINUM(2+) ION A. J. P. ALIX, A. J. P. ALIXSearch for more papers by this authorM. MANFAIT, M. MANFAITSearch for more papers by this authorB. N. CYVIN, B. N. CYVINSearch for more papers by this authorS. J. CYVIN, S. J. CYVINSearch for more papers by this authorB. J. VAN DER VEKEN, B. J. VAN DER VEKENSearch for more papers by this authorT. THEOPHANIDES, T. THEOPHANIDESSearch for more papers by this author A. J. P. ALIX, A. J. P. ALIXSearch for more papers by this authorM. MANFAIT, M. MANFAITSearch for more papers by this authorB. N. CYVIN, B. N. CYVINSearch for more papers by this authorS. J. CYVIN, S. J. CYVINSearch for more papers by this authorB. J. VAN DER VEKEN, B. J. VAN DER VEKENSearch for more papers by this authorT. THEOPHANIDES, T. THEOPHANIDESSearch for more papers by this author First published: October 30, 1979 https://doi.org/10.1002/chin.197944001AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue44October 30, 1979 RelatedInformation

Molecular vibrations of complexes with trigonal ligands: Part X. The T model of Zr(BH 4) 4 with calculated mean amplitudes

A normal coordinate analysis of Zr(BH 4) 4 was performed on the basis of a T model for the molecule. The shifts in mean amplitudes when passing from T d to T are discussed. The force field was refined by means of the latest vibrational spectroscopic data from the literature, and the complete sets of mean amplitudes and perpendicular amplitude correction coefficients are given. The refined force field was finally applied to the Zr(BD 4) 4 isotopic molecule.

Molecular vibrations of complex with trigonal ligands

A normal coordinate analysis was performed for the compound [Pt(NH3 )4 ]2+ which has a square planar framework structure (PtN4 with local symmetry D4h ) and tetrahedral NH3 groups (local symmetry C3v ). C4h over-all structure was assumed (two opposite animine groups are considered to be in staggered position). Two general valence force fields which reproduce satisfactorily the observed frequencies for the whole complex as well as the H/D isotopic derivative have been developped. These calculations for the whole complex (C4h ) are compared with the point mass model approximation (PtN'4 , D4h with mN' , = mNH3 ), the validity of which is confirmed. Finally the refined force field for [Pt(NH3 )4 ]2+ was used to calculate the frequencies of various isotopes (14 N/15 N, H/D) and the mean amplitudes at absolute zero and 298 °K of the mother molecule.

Molecular vibrations of complexes with trigonal ligands: Part IX. Zr(BH 4) 4

The molecular vibrations of Zr(BH 4) 4 are analysed on the basis of a T d model. Symmetry coordinates are described and classified into those of ligand vibrations and central-part vibrations. A simple force field is deduced, which gives satisfactory agreement with experimental vibrational frequencies and mean amplitudes of vibration. A continuation of the work by considering the probably more realistic T model is suggested.

Molecular Vibration Analysis of the TeCl4 Tetramer and Monomer and the SeCl4 Tetramer

Abstract The molecular vibrations of (TeCl4)4 and (SeCl4)4 are studied on the basis of a cubane-like Td model. Symmetry coordinates are produced by using the theory developed for tetrahedral complexes with trigonal ligands. Approximate vibrational frequencies are calculated from very simple four-parameter force fields and used as an aid in tentative assignments of observed frequencies from literature. Next the force fields are refined by adjustments to the observed frequencies assigned as fundamentals. Potential energy distribution terms and mean amplitudes of vibration are calculated. Finally the monomeric form of TeCl4 is analysed, mainly in order to show the frequency shifts on passing from the monomer to tetramer.

Molecular vibrations of complexes with trigonal ligands: Part VIII. Pt(PF 3) 4, Pd(PF 3) 4 and Ni(PF 3) 4

Molecular vibrations of complexes with trigonal ligands: Part VIII. Pt(PF 3) 4, Pd(PF 3) 4 and Ni(PF 3) 4

ChemInform Abstract: MOLECULAR VIBRATIONS OF COMPLEXES WITH TRIGONAL LIGANDS. VII‐ HEXAAMMINES WITH AN OCTAHEDRAL SKELETON, APPLICATION TO HEXAAMMINENICKEL(2+)

Chemischer InformationsdienstVolume 7, Issue 29 Physical Inorganic Chemistry ChemInform Abstract: MOLECULAR VIBRATIONS OF COMPLEXES WITH TRIGONAL LIGANDS. VII- HEXAAMMINES WITH AN OCTAHEDRAL SKELETON, APPLICATION TO HEXAAMMINENICKEL(2+) B. N. CYVIN, B. N. CYVINSearch for more papers by this authorS. J. CYVIN, S. J. CYVINSearch for more papers by this authorK. H. SCHMIDT, K. H. SCHMIDTSearch for more papers by this authorA. MUELLER, A. MUELLERSearch for more papers by this authorJ. BRUNVOLL, J. BRUNVOLLSearch for more papers by this author B. N. CYVIN, B. N. CYVINSearch for more papers by this authorS. J. CYVIN, S. J. CYVINSearch for more papers by this authorK. H. SCHMIDT, K. H. SCHMIDTSearch for more papers by this authorA. MUELLER, A. MUELLERSearch for more papers by this authorJ. BRUNVOLL, J. BRUNVOLLSearch for more papers by this author First published: July 20, 1976 https://doi.org/10.1002/chin.197629002AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume7, Issue29July 20, 1976 RelatedInformation

Molecular vibrations of complexes with trigonal ligands: VII: Hexammines with an octahedral skeleton, application to [Ni(NH 3) 6] 2+

A vibrational analysis is performed for [Ni(NH 3) 6] 2+, which has an octahedral framework structure. The D 3d structure was assumed for the whole complex. Symmetry coordinates are given for all the vibrational modes, which are classified as (a) ligand vibrations, (b) ligand-framework couplings, and (c) framework vibrations. The correlations with the framework O h and ligand C 3v symmetries are worked out. An approximate force field based on the ligand-framework correlated coordinates is developed. It reproduces satisfactorily the observed frequencies for four isotopic ions of[Ni(NH 3) 6] 2+. Approximate calculations for the point-mass model (XY 6) are compared with those of the whole complex. The validity of the point-mass model approximation is confirmed.

Molecular vibrations of complexes with trigonal ligands. Part V. Symmetry coordinates for tetrahedral complexes

Ligands of C 3V symmetry are assumed to be a part of a T d complex. Suitable combinations of C 3v ( a 2 + e) symmetry coordinates, which fit into the T d model, are studied. The results constitute a useful supplement to the C 3V ( a 1 + e) type coordinates studied previously. Torsional coordinates in the Ni(PF 3) 4 type model are treated in particular.

Molecular vibrations of complexes with trigonal ligands: VI: Tetrammines with a square-planar-skeleton- the infrared spectrum of [Cu( 15NH 3) 4] 2+

A vibrational analysis is performed for [Cu(NH 3) 4] 2+, which has a square-planar frame work structure. Two versions of symmetry coordinates are produced assuming the C 4V and C 4h structures, respectively. The IR spectrum of [Cu( 15NH 3) 4] 2+ was recorded, and the observed frequencies used as supplementary data in a normal coordinate analysis along with data available for other isotopic compounds. An approximate force field which reproduces satisfactorily the observed frequencies for all the isotopic compounds is developed. The force constants may be classified as pertaining to the (a) ligand vibrations, (b) ligand-framework couplings and (c) framework vibrations. These calculations for the whole complex are compared with (i) results for free NH 3, (ii) the analysis of the XY 4 ( D 4h) point-mass model and (iii) calculations for the pyramidal-axial CuNH 3 ( C 3V) fragment. It is concluded that the effects of kinematic coupling are small. The validity of the point-mass model approximation is confirmed.