Six polycyclic pyrimidoazepine derivatives: syntheses, molecular structures and supramolecular assembly

2016 ◽  
Vol 72 (4) ◽  
pp. 346-357 ◽  
Author(s):  
Lina M. Acosta Quintero ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Supramolecular Assembly ◽  
Molecular Structures ◽  
Conventional Heating ◽  
Substitution Reactions ◽  
Methyl Group ◽  
Different Types ◽  
Boat Form ◽  
Conformation Intermediate ◽  
Basic Solutions ◽  
Axial Site

A versatile synthetic method has been developed for the formation of variously substituted polycyclic pyrimidoazepine derivatives, formed by nucleophilic substitution reactions on the corresponding chloro-substituted compounds; the reactions can be promoted either by conventional heating in basic solutions or by microwave heating in solvent-free systems. Thus, (6RS)-6,11-dimethyl-3,5,6,11-tetrahydro-4H-benzo[b]pyrimido[5,4-f]azepin-4-one, C14H15N3O, (I), was isolated from a solution containing (6RS)-4-chloro-8-hydroxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepine and benzene-1,2-diamine; (6RS)-4-butoxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-8-ol, C18H23N3O2, (II), was formed by reaction of the corresponding 6-chloro compound with butanol, and (RS)-4-dimethylamino-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-8-ol, C16H20N4O, (III), was formed by reaction of the chloro analogue with alkaline dimethylformamide. (6RS)-N-Benzyl-8-methoxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-4-amine, C22H24N4O, (IV), (6RS)-N-benzyl-6-methyl-1,2,6,7-tetrahydropyrimido[5′,4′:6,7]azepino[3,2,1-hi]indol-8-amine, C22H22N4, (V), and (7RS)-N-benzyl-7-methyl-2,3,7,8-tetrahydro-1H-pyrimido[5′,4′:6,7]azepino[3,2,1-ij]quinolin-9-amine, C23H24N4, (VI), were all formed by reaction of the corresponding chloro compounds with benzylamine under microwave irradiation. In each of compounds (I)–(IV) and (VI), the azepine ring adopts a conformation close to the boat form, with the C-methyl group in a quasi-equatorial site, whereas the corresponding ring in (V) adopts a conformation intermediate between the twist-boat and twist-chair forms, with the C-methyl group in a quasi-axial site. No two of the structures of (I)–(VI) exhibit the same range of intermolecular hydrogen bonds: different types of sheet are formed in each of (I), (II), (V) and (VI), and different types of chain in each of (III) and (IV).

Metaphoric chains

2021 ◽  
Vol 19 (2) ◽  
pp. 273-298
Author(s):  
Sakineh Navidi-Baghi ◽  
Ali Izanloo ◽  
Alireza Qaeminia ◽  
Alireza Azad
Keyword(s):  
Molecular Structure ◽  
Conceptual Metaphor ◽  
Previous Literature ◽  
Molecular Structures ◽  
Conceptual Metaphor Theory ◽  
Metaphor Theory ◽  
Different Types ◽  
New Form

Abstract The molecular structure of a complex metaphor comprises two or more atomic metaphorical parts, known as primary metaphors. In the same way, several molecular structures of metaphors may combine and form a mixture, known as mixed metaphors. In this study, different types of metaphoric integrations are reviewed and illustrated in figures to facilitate understanding the phenomena. Above all, we introduce double-ground metaphoric chain, a new form of metaphoric integration that has not been identified in the previous literature. Also, a distinction is made between single-ground and double-ground metaphoric chains. In the former, which has already been introduced, two basic metaphors are chained with the same form and have the same ground, while the latter includes two chained metaphors, one main metaphor plus a supportive one, with different grounds. In this analysis, we benefited from Conceptual Metaphor Theory (CMT) to analyse double-ground metaphoric chains. This study suggests that each metaphoric integration leads to a multifaceted conceptualization, in which each facet is related to one of the constituent micro-metaphors.

Obtaining of Collagen Extracts Used as Biomaterials with Applications in the Medical Field

2020 ◽  
Vol 3 (2) ◽  
pp. 84
Author(s):  
Melat Cherim ◽  
Rodica Sîrbu
Keyword(s):  
Core Protein ◽  
Morphological Structure ◽  
Molecular Structures ◽  
Supramolecular Organization ◽  
Connective Tissues ◽  
Medical Field ◽  
Genetic Types ◽  
Nano Structures ◽  
Different Types ◽  
And Function

Collagen is the core protein of connective tissues: skin, bone, tendon, base membrane, etc. Collagen is actually a family of several different genetic types. Currently they are known, in vertebrates, at least 27 different types of collagens, which shows a remarkable diversity in molecular and supramolecular organization of the tissue distribution and function, discovered and developed over 45 years. They were studied, in detail, 12 main types. Collagen-based bioproducts can be produced in a variety of molecular structures (micro and nano structures) in powder form, hydrogels and injectable solutions, films, membranes and matrices, etc. This paper presents the drying processes that are selected depending on the nature of the extract (undenatured or denatured) and morphological structure bioproduct or sponge, fibers or membranes. The most frequently used procedures for drying are freeze-drying and free drying at a temperature of approx. 25 ° C. Both processes produce no distorts to the extracts They are presented bioproducts derived from collagen which are used in medicine.

A combined QM/MM study of ligand substitution enthalpies in the L2Fe(CO)3, RuCpL2Cl, and RuCp*L2Cl systems

1998 ◽  
Vol 76 (10) ◽  
pp. 1457-1466 ◽  
Author(s):  
Luigi Cavallo ◽  
Tom K Woo ◽  
Tom Ziegler
Keyword(s):  
Experimental Data ◽  
Key Words ◽  
Molecular Mechanics ◽  
Density Functional ◽  
Ligand Substitution ◽  
Organometallic Complexes ◽  
Molecular Structures ◽  
Substitution Reactions ◽  
Good Accord ◽  
Steric Influence

A combined density functional and molecular mechanics approach (QM/MM) has been validated in a study of the substitution reactions: (i) (PH3)2Fe(CO)3 + 2ER3 ⇆ (ER3)2Fe(CO)3 + 2PH3(ER3 = PMe3, PEt3, PMePh2, PPh3, PCyPh2, PiPr3, PBz3, PCy3, AsEt3, AsPh3); and (ii) Cp'Ru(PH3)2Cl + 2ER3 ⇆ Cp'Ru(ER3)2Cl + 2PH3 (Cp' = C5H5, C5(CH3)5; ER3 = PMe3, PEt3, PnBu3, PMe2Ph, PMePh2, PPh3, AsEt3, P(OMe)3, P(OPh)3, P(OCH2)3CEt). The steric influence of the R substituents on the substitution enthalpies correlates well with experimental data. The combined QM/MM approach is also able to afford molecular structures in good accord with experimental estimates. Key words: combined QM/MM, ligand substitutions, organometallic complexes.

Effects of a thickener structure on grease elastohydrodynamic lubrication films

2000 ◽  
Vol 214 (4) ◽  
pp. 327-336 ◽  
Author(s):  
M Kaneta ◽  
T Ogata ◽  
Y Takubo ◽  
M Naka
Keyword(s):  
Film Thickness ◽  
Direct Observation ◽  
Film Formation ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Speed ◽  
Molecular Structures ◽  
Optimum Temperature ◽  
Oil Viscosity ◽  
Base Oil ◽  
Different Types

The effects of the thickener structure and base oil viscosity on the grease film formation in rolling point elastohydrodynamic contacts have been discussed on the basis of direct observation using the optical interferometry technique. Three different types of diurea greases without additives have been used as test greases. As the base oils three kinds of ether-type synthetic oils having similar molecular structures but different viscosities were used. The film behaviour of fresh greases has also been compared with that of the degraded greases. It has been found that the behaviour of grease elastohydrodynamic lubrication films is basically influenced by the thickener structure and base oil viscosity. The adhesion or deposition of the thickener on the contacting surfaces and oil starvation which affect film formation depend on the thickener structure, base oil viscosity and rolling speed. Furthermore, it has been suggested that there is an optimum temperature which gives a maximum film thickness according to the consistency of the grease.

Optical Property and Photoisomerization of Some Functional Azobenzene Derivatives with Aromatic Substituted Groups

2011 ◽  
Vol 121-126 ◽  
pp. 1009-1013
Author(s):  
Ti Feng Jiao ◽  
Xu Hui Li ◽  
Qiu Rong Li ◽  
Jing Xin Zhou
Keyword(s):  
Molecular Structure ◽  
Optical Property ◽  
Potential Application ◽  
Uv Light ◽  
Molecular Structures ◽  
Functional Material ◽  
Methyl Group ◽  
Uv Light Irradiation ◽  
The Difference ◽  
Azobenzene Derivatives

Some functional azobenzene derivatives with aromatic substituted groups have been synthesized and their photoisomerization have also been investigated. It has been found that depending on different substituted groups, such as phenyl or naphthyl segments, the formed azobenzene derivatives showed different properties, indicating distinct regulation of molecular skeletons. Spectral data confirmed commonly the characteristic absorption of substituted groups and aromatic segments in molecular structures. In addition, the photoisomerization of all compounds in solution can show trans-to-cis photoisomerization by UV light irradiation, and demonstrate distinct isomerization ratio depending on effect of different substituted headgroups. The difference is mainly attributed to the aromatic substituted headgroups and methyl group in molecular structure. The present results have showed that the special properties of azobenzene derivatives could be effectively turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in sensor and functional material field.

scholarly journals Structural Study of Three 1,2,4-triazole Derivatives Prepared by Oxidative Cyclization of Thiosemicarbazides

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 20
Author(s):  
Mirian Artime ◽  
Alfonso Castiñeiras ◽  
Isabel García-Santos ◽  
Manuel Saa
Keyword(s):  
Acetic Acid ◽  
Single Crystal ◽  
Structural Study ◽  
Supramolecular Assembly ◽  
Oxidative Cyclization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triazole Derivatives

In the present research, 5,5-dimethyl-4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3-thione (1) was prepared by condensation from N-phenylhydrazinecarbothioamide, while 4-phenyl-5-(pyrazin-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (2) and 2-((5-(pyridin-2-yl) -4H-1,2,4-triazol-3-yl)thio)acetic acid (3) was prepared by oxidative cyclization from 2-(amino(pyrazin-2-yl)methylene)-N-phenylhydrazine-1-carbothioamide and 2-(amino(pyridine-2-yl)methylene)hydrazine-1-carbothioamide, respectively. The three compounds have been well characterized and their molecular structures studied by single-crystal X-ray diffraction. The supramolecular assembly of each crystal has also been analyzed and discussed.

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