scholarly journals Synthesis and structural characterization of four dichloridobis(cyclopropylalkynylamidine)metal complexes

2018 ◽  
Vol 74 (11) ◽  
pp. 1658-1664
Author(s):  
Sida Wang ◽  
Phil Liebing ◽  
Felix Engelhardt ◽  
Liane Hilfert ◽  
Sabine Busse ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Structural Characterization ◽  
Triple Bond ◽  
Spectroscopic Data ◽  
Central Metal Atom ◽  
Central Metal ◽  
Elemental Analyses ◽  
Hydrolysis Of ◽  
Cl Atoms

Deliberate hydrolysis of lithium cyclopropylalkynylamidinates, Li[c-C3H5—C[triple-bond]C(NR′)2] [R′ = i Pr, Cy = cyclohexyl)], afforded the hitherto unknown neutral cyclopropylalkynylamidine derivatives c-C3H5—C[triple-bond]C—C(NR′)(NHR′) [R′ = i Pr (1), Cy (2)]. Subsequent reactions of 1 or 2 with metal(II) chlorides, MCl2 (M = Mn, Fe, Co), provided the title complexes dichloridobis(3-cyclopropyl-N,N′-diisopropylprop-2-ynamidine)manganese(II), [MnCl2(C12H20N2)2], (3), dichloridobis(3-cyclopropyl-N,N′-diisopropylprop-2-ynamidine)iron(II), [FeCl2(C12H20N2)2], (4), dichloridobis(N,N′-dicyclohexyl-3-cyclopropylprop-2-ynamidine)iron(II), [FeCl2(C18H28N2)2], (5), and dichloridobis(N,N′-dicyclohexyl-3-cyclopropylprop-2-ynamidine)cobalt(II), [CoCl2(C18H28N2)2], (6), or more generally MCl2[c-C3H5—C[triple-bond]C—C(NR′)(NHR′)]2 [R′ = i Pr, M = Mn (3), Fe (4); R′ = Cy, M = Fe (5), Co (6)] in moderate yields (30–39%). Besides their spectroscopic data (IR and MS) and elemental analyses, all complexes 3–6 were structurally characterized. The two isopropyl-substituted complexes 3 and 4 are isotypic, and so are the cyclohexyl-substituted complexes 5 and 6. In all cases, the central metal atom is coordinated by two Cl atoms and two N atoms in a distorted-tetrahedral fashion, and the structure is supported by intramolecular N—H...Cl hydrogen bonds.

4-(Piperidin-1-yl)pyridinium hexafluorophosphate at 150 K

2003 ◽  
Vol 59 (11) ◽  
pp. o622-o624 ◽  
Author(s):  
Bruce D. James ◽  
Siti Mutrofin ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Hydrogen Bonds ◽  
Structural Characterization ◽  
Title Compound ◽  
Ion Pairs ◽  
Piperidine Ring ◽  
Torsion Angles ◽  
Compound C ◽  
Counter Ions

Structural characterization of the title compound, C10H15N2 +·PF6 −, shows it to be ionic, with the pyridine rather than the piperidine N atom being protonated and forming hydrogen bonds to the counter-ions, resulting in two independent ion pairs. A number of unusual features are noted, in particular the remarkably close inter-ring hydrogen contacts [1.97 (3)–2.00 (3) Å] and the considerable differences in the pair of cations, in respect of the torsion angles within the piperidine ring involving the bonds to either side of the N atom.

scholarly journals Antimicrobial, Antifertility and Antiinflammatory Approach to Tetradentate Macrocyclic Complexes of Iron(II) and Manganese(II)

2002 ◽  
Vol 8 (6) ◽  
pp. 347-353 ◽  
Author(s):  
Ashu Chaudhary ◽  
D. P. Jaroli ◽  
R. V. Singh
Keyword(s):  
Molecular Weight ◽  
Reproductive Organs ◽  
Spectral Studies ◽  
Central Metal Atom ◽  
Central Metal ◽  
Testicular Sperm ◽  
Mass Spectral ◽  
Sperm Density ◽  
Elemental Analyses

Some antifertility inhibitors of 18 to 24-membered tetraazamacrocyclic complexes of iron(II) and manganese(II) have been synthesised by the template condensation using 1,3-phenylenediamine with malonic acid, succinic acid, glutaric acid and adipic acid. The reaction proceed smoothly to completion. The complexes were characterized by elemental analyses, molecular weight determinations, infrared, electronic, magnetic moment, mössbaur and mass spectral studies. The elemental analyses are consistent with the formation of the complexes [M(N4Ln)Cl2] (M = Fe(lI) or Mn(II)). All these complexes are stable and monomeric in nature as indicated by the molecular weight determinations. The spectral studies confirm the octahedral geometry around the central metal atom. The complexes have been screened in vitro against a number of fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trials and biochemical parameters of reproductive organs have been examined and discussed.

Synthesis, crystallization, X-ray structural characterization and solid-state assembly of a cyclic hexapeptoid with propargyl and methoxyethyl side chains

2017 ◽  
Vol 73 (3) ◽  
pp. 399-412 ◽  
Author(s):  
Consiglia Tedesco ◽  
Eleonora Macedi ◽  
Alessandra Meli ◽  
Giovanni Pierri ◽  
Giorgio Della Sala ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Structural Characterization ◽  
Crystal Form ◽  
Side Chains ◽  
Crystal Forms ◽  
Hydrate Crystal ◽  
The Stability ◽  
Efficient Packing

The synthesis and the structural characterization of a cyclic hexapeptoid with four methoxyethyl and two propargyl side chains have disclosed the presence of a hydrate crystal form [form (I)] and an anhydrous crystal form [form (II)]. The relative amounts of form (I) and form (II) in the as-purified product were determined by Rietveld refinement and depend on the purification procedures. In crystal form (I), peptoid molecules assemble in a columnar arrangement by means of side-chain-to-backbone C=CH...OC hydrogen bonds. In the anhydrous crystal form (II), cyclopeptoid molecules form ribbons by means of backbone-to-backbone CH2...OC hydrogen bonds, thus mimicking β-sheet secondary structures in proteins. In both crystal forms side chains act as joints among the columns or the ribbons and contribute to the stability of the whole solid-state assembly. Water molecules in the hydrate crystal form (I) bridge columns of cyclic peptoid molecules, providing a more efficient packing.

Preparation and Characterization of Y3Al5O12 (YAG) from An Alkoxide-Derived Polymer

1992 ◽  
Vol 286 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Infrared Spectroscopy ◽  
Yttrium Aluminum Garnet ◽  
Polymeric Materials ◽  
Pyrolysis Products ◽  
Elemental Analyses ◽  
Yttrium Aluminum ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

ABSTRACTThe controlled hydrolysis of Al(O-sec-Bu)3 and Y(O-iso-Pr)3 or the reaction of Y(OOCCH)3 with partially hydrolyzed Al(O-sec-Bu)3 [AlO0.75(O-sec-Bu)1.5] resulted in the formation of soluble polymeric materials. Pyrolysis of these materials under a flow of oxygen led to the formation of yttrium aluminum garnet (YAG) at 650-1500°C. YAG was the only crystalline phase observed during pyrolysis, and the Al/Y ratio of the pyrolysis products and the starting material was identical. However, infrared spectroscopy indicated that carbonate groups and entrained CO2 existed in the products at temperatures up to 1250°C. The pyrolysis chemistry of the precursors and the microstructure of the products were studied by FT-IR, TGA, XRD, SEM and elemental analyses.

Synthesis and Structural Characterization of a Terminal Hydroxide Containing Alumoxane via Hydrolysis of Aluminum Hydrides

2004 ◽  
Vol 43 (4) ◽  
pp. 1217-1219 ◽  
Author(s):  
Ying Peng ◽  
Guangcai Bai ◽  
Hongjun Fan ◽  
Denis Vidovic ◽  
Herbert W. Roesky ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Aluminum Hydrides ◽  
Hydrolysis Of

scholarly journals A novel decrystallizing protein CxEXL22 from Arthrobotrys sp. CX1 capable of synergistically hydrolyzing cellulose with cellulases

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rong Li ◽  
Yunze Sun ◽  
Yihao Zhou ◽  
Jiawei Gai ◽  
Linlu You ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Hydrophobic Surface ◽  
Crystalline Cellulose ◽  
Crystalline Region ◽  
Strong Activity ◽  
Hydrophobic Residues ◽  
Cellulose Accessibility ◽  
Hydrolysis Of ◽  
Β Sheet

AbstractA novel expansin-like protein (CxEXL22) has been identified and characterized from newly isolated Arthrobotrys sp. CX1 that can cause cellulose decrystallization. Unlike previously reported expansin-like proteins from microbes, CxEXL22 has a parallel β-sheet domain at the N terminal, containing many hydrophobic residues to form the hydrophobic surface as part of the groove. The direct phylogenetic relationship implied the genetic transfers occurred from nematode to nematicidal fungal Arthrobotrys sp. CX1. CxEXL22 showed strong activity for the hydrolysis of hydrogen bonds between cellulose molecules, especially when highly crystalline cellulose was used as substrate. The hydrolysis efficiency of Avicel was increased 7.9-fold after pretreating with CxEXL22. The rupture characterization of crystalline region indicated that CxEXL22 strongly binds cellulose and breaks up hydrogen bonds in the crystalline regions of cellulose to split cellulose chains, causing significant depolymerization to expose much more microfibrils and enhances cellulose accessibility.

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