scholarly journals Various Structural Types of Cyanide-Bridged FeIII–MnIII Bimetallic Coordination Polymers (CPs) and Polynuclear Clusters Based-on A New mer-Tricyanoiron(III)Building Block: Synthesis, Crystal Structures, and Magnetic Properties

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1585
Author(s):  
Wenlong Lan ◽  
Xiaoyun Hao ◽  
Yong Dou ◽  
Zhen Zhou ◽  
Lu Yang ◽  
...  
Keyword(s):  
Cyano Group ◽  
Linear Chain ◽  
Magnetic Coupling ◽  
1D Chain ◽  
Structure Correlation ◽  
Cyano Groups ◽  
Coordinated Water ◽  
In Cis ◽  
Polynuclear Clusters ◽  
Base Compound

Four cyanide-bridged FeIII–MnIII complexes {[Fe(qxcq)(CN)3][Mn(L1)(H2O)]}[Mn(L1)(H2O)(CH3OH)](ClO4)·1.5MeOH·0.5H2O (L1 = N,N′-bis(3-methoxy-5-bromosalicylideneiminate) (2), {[Fe(qxcq)(CN)3][Mn(L2)]}2·0.5H2O (L2 = N,N′-ethylene-bis(3-ethoxysalicylideneiminate)) (3), [Fe(qxcq)(CN)3][Mn(L3)] (L3 = bis(acetylacetonato)ethylenediimine) (4), [Fe(qxcq)(CN)3][Mn(L4)]·1.5MeOH·0.5CH3CN·0.25H2O (L4 = N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate)) (5), were prepared by assembling a new structurally characterized mer-tricyanoiron(III) molecular precursor (Ph4P)[Fe(qxcq)(CN)3]·0.5H2O (qxcq− = 8-(2-quinoxaline-2-carboxamido)quinoline anion) (1) and the corresponding manganese(III) Schiff base compound. Complexes 2and 3containa cyanide-bridged heterobimetallic dinuclear entity, which can be further dimerized by self-complementary H-bond interactions through the coordinated water molecule from one complex and the free O4unit from the adjacent complex. Complexes 4 and 5 area one-dimensional coordination polymer (CP) comprised of the repeated [Mn(Schiffbase)-Fe(qxcq)(CN)3] units. Complex 4 shows a linear-chain conformation with two trans-located cyano groups bridgingthe neighboring Mn units, while complex 5 is a zigzag-like 1D CP, where the two cyano groups in cis configurationfunction as bridges. In bothcomplexes 4 and 5, the inter-chain π–πstack interactions within the aromaticrings of cyanide precursor extend the 1D chain into the supermolecular 2D networks. The magnetic property has been experimentally studied and theoretically fitted over the four Fe(III)-Mn(III) complexes, revealing the antiferromagnetic interaction in complexes 2 and 4 and the unusual ferromagnetic coupling in complexes 3 and 5 between the Fe(III) ion and the Mn(III) ion bridged by the cyano group. Furthermore, the different magnetic coupling nature has been analyzed on the basis of the magneto-structure correlation of the mer-tricyanometallate-based Fe(III)-Mn(III) magnetic system.

scholarly journals Versatility of the Cyano Group in Intermolecular Interactions

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4495
Author(s):  
Steve Scheiner
Keyword(s):  
Intermolecular Interactions ◽  
Lewis Acid ◽  
Electrostatic Potential ◽  
Cyano Group ◽  
Acid Molecule ◽  
Cyclic System ◽  
Precise Nature ◽  
Noncovalent Bond ◽  
Positive Region ◽  
Cyano Groups

Several cyano groups are added to an alkane, alkene, and alkyne group so as to construct a Lewis acid molecule with a positive region of electrostatic potential in the area adjoining these substituents. Although each individual cyano group produces only a weak π-hole, when two or more such groups are properly situated, they can pool their π-holes into one much more intense positive region that is located midway between them. A NH3 base is attracted to this site, where it forms a strong noncovalent bond to the Lewis acid, amounting to as much as 13.6 kcal/mol. The precise nature of the bonding varies a bit from one complex to the next but typically contains a tetrel bond to the C atoms of the cyano groups or the C atoms of the linkage connecting the C≡N substituents. The placement of the cyano groups on a cyclic system like cyclopropane or cyclobutane has a mild weakening effect upon the binding. Although F is comparable to C≡N in terms of electron-withdrawing power, the replacement of cyano by F substituents substantially weakens the binding with NH3.

The Total Synthesis of Spermine Alkaloid Kukoamine Bimesylate

Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2669-2672
Author(s):  
Kai Dong
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Addition Reaction ◽  
Cyano Group ◽  
Michael Addition Reaction ◽  
Amino Groups ◽  
Competitive Reaction ◽  
12 Steps ◽  
Cyano Groups

The first total synthesis of kukoamine B bimesylate was completed from 1,4-diaminobutane dihydrochloride in 12 steps with a 11.4% overall yield, and all the steps could be carried out at a kilogram scale. The cyano groups were used as the precursor of amino groups to avoid the competitive reaction delicately. The aza-Michael addition reaction, amidation and hydrogenation of the cyano group sequence was streamlined as a general approach towards the synthesis of polyamine structures.

Two cadmium(II) fluorous coordination compounds tuned by different bipyridines

2017 ◽  
Vol 73 (5) ◽  
pp. 424-429 ◽  
Author(s):  
Ya-Jie Kong ◽  
Peng Li ◽  
Li-Juan Han ◽  
Lu-Tong Fan ◽  
Peng-Peng Li ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Coordination Compounds ◽  
Linear Chain ◽  
Three Dimensional ◽  
Chain Structure ◽  
Water Molecules ◽  
Hydrogen Bond Acceptor ◽  
Small Surface ◽  
One Dimensional ◽  
Coordinated Water

Fluorine is the most electronegative element and can be used as an excellent hydrogen-bond acceptor. Fluorous coordination compounds exhibit several advantageous properties, such as enhanced high thermal and oxidative stability, low polarity, weak intermolecular interactions and a small surface tension compared to hydrocarbons. C—H...F—C interactions, although weak, play a significant role in regulating the arrangement of the organic molecules in the crystalline state and stabilizing the secondary structure. Two cadmium(II) fluorous coordination compounds formed from 2,2′-bipyridine, 4,4′-bipyridine and pentafluorobenzoate ligands, namely catena-poly[[aqua(2,2′-bipyridine-κ2 N,N′)(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-2,3,4,5,6-pentafluorobenzoato-κ2 O:O′], [Cd(C7F5O2)2(C10H8N2)(H2O)] n , (1), and catena-poly[[diaquabis(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-4,4′-bipyridine-κ2 N:N′], [Cd(C7F5O2)2(C10H8N2)(H2O)2] n , (2), have been synthesized solvothermally and structurally characterized. Compound (1) shows a one-dimensional chain structure composed of Cd—O coordination bonds and is stabilized by π–π stacking and O—H...O hydrogen-bond interactions. Compound (2) displays a one-dimensional linear chain structure formed by Cd—N coordination interactions involving the 4,4′-bipyridine ligand. Adjacent one-dimensional chains are extended into two-dimensional sheets by O—H...O hydrogen bonds between the coordinated water molecules and adjacent carboxylate groups. Moreover, the chains are further linked by C—H...F—C interactions to afford a three-dimensional network. In both structures, hydrogen bonding involving the coordinated water molecules is a primary driving force in the formation of the supramolecular structures.

ChemInform Abstract: Magnetic Coupling in a Linear-Chain Copper(II)-Imidazolate Compound.

1986 ◽  
Vol 17 (24) ◽  
Author(s):  
A. BENCINI ◽  
C. BENELLI ◽  
D. GATTESCHI ◽  
C. ZANCHINI
Keyword(s):  
Linear Chain ◽  
Magnetic Coupling

scholarly journals catena-Poly[[aquazinc(II)]-μ-N,N′-bis(2-cyano-3-ethoxy-3-oxoprop-1-enyl)benzene-1,2-diaminido]

2014 ◽  
Vol 70 (5) ◽  
pp. m187-m188
Author(s):  
Monica Fuchs ◽  
Thomas Zevaco ◽  
Eckhard Dinjus ◽  
Olaf Walter
Keyword(s):  
Solvent Molecule ◽  
Binding Mode ◽  
Asymmetric Unit ◽  
Apical Position ◽  
Water Solvent ◽  
Octahedral Environment ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Cyano Groups ◽  
Coordinated Water

The slightly yellow-coloured title complex, [Zn(C18H16N4O4)(H2O)]n, crystallizes with one molecule in the asymmetric unit. The structure clearly shows themer-η4O,O,N,N-binding mode of theN,N′-bis-(2-cyano-ethylpropenoyl)-1,2-diamidobenzene ligand stabilizing the Zn centre of a distorted octahedral environment. The fifth coordination site in one apical position is held by a coordinating solvent water molecule whereas the complete octahedral coordination sphere is completed by coordination of one N atom from a CN group of a neighbouring molecule, leading to the final polymeric structure consisting of zigzag staggered chains in parallel orientation along thec-axis direction. Between the coordinated water solvent molecule and the N atoms of uncoordinated cyano-groups of neighboured units, two H-bridge bonds are formed. One of these H-bridge bonds is of inter- whereas the other of intra-strand nature, leading to a two-dimensional network parallel to (110) stabilizing the supramolecular structure. Six Zn—O or Zn—N bonds are found with lengths ranging from 2.061 (1) to 2.185 (1) Å and bond angles about the Zn atom are clustered in the ranges 79.83 (4)–104.21 (4) and 167.05 (4)–170.28 (4)°.

DFT investigation on organic dyes with cross-conjugated cyano groups

2014 ◽  
Vol 13 (01) ◽  
pp. 1450008
Author(s):  
Chunhe Yang ◽  
Aiwei Tang ◽  
Fujun Zhang ◽  
Feng Teng
Keyword(s):  
Density Functional ◽  
Molecular Conformation ◽  
Organic Dyes ◽  
Cyano Group ◽  
Energy Levels ◽  
Orbital Energy ◽  
Dye Molecules ◽  
Conjugated Molecules ◽  
Functional Theory ◽  
Cyano Groups

Organic dye molecules with the acceptor moieties, cyano groups, cross-conjugated to the donor moieties, have been investigated theoretically. Density functional theory (DFT) calculations on such cross-conjugated molecules reveal the effects of cross-conjugation on the geometric and electronic structures of the molecules. The cross-conjugated cyano groups in the dye molecules are found effective to alter the charge population and the frontier orbital energy levels of the dyes. The effects of cross-conjugation of cyano group on the molecular conformation, the charge transfer, and polarity of the dyes are discussed.

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