Methyl 2-[N-(2′-Pyridylmethyl)carbamyl]pyridine-6-carboxylate: A Precursor for Unsymmetrical Diamide Ligands

2006 ◽  
Vol 59 (11) ◽  
pp. 796 ◽  
Author(s):  
Mery Napitupulu ◽  
Geoffrey A. Lawrance ◽  
Guy J. Clarkson ◽  
Peter Moore
Keyword(s):  
Ester Group ◽  
Crystal Structure Analysis ◽  
Membered Ring ◽  
The Other ◽  
Tridentate Ligand ◽  
Carboxylate Group ◽  
Amido Group ◽  
Group A ◽  
Pentadentate Ligands ◽  
Diamide Ligands

Methyl 2-[N-(2′-pyridylmethyl)carbamyl]pyridine-6-carboxylate (H1), prepared by reaction of a 1:1 ratio of the methyl diester of pyridine-2,6-dicarboxylic acid and 2-aminomethylpyridine, can form 1:2 M:L complexes by acting as a tridentate ligand, as exemplified by a crystal structure analysis of [CoIII(1)2](ClO4) where each ligand is coordinated by the amido group and its two flanking pyridine groups, with the ester group, a relatively poor donor, remaining unbound. The acid formed upon ester hydrolysis, hydrogen 2-[N-(2′-pyridylmethyl)carbamyl]pyridine-6-carboxylate (H22), has been isolated as the ammonium salt, and forms a 2:2 M:L dimer [CuII2(2)2(OH2)2] where each ligand binds to one copper through the amido group, its flanking pyridine groups, and to the other copper by the carboxylate group, to form a 10-membered ring that incorporates both metals. Onward reaction of the monoester (H1) with a different amine leads to potentially pentadentate ligands centred on a 2,6-disubstituted pyridine but with unsymmetrical arms, as exemplified by synthesis of 2-[N-(2′-pyridylmethyl)carbamyl]-6-[N-(2′-pyridylethyl)carbamyl]pyridine (H23), 2-[N-(2′-pyridylmethyl)carbamyl]-6-[N-(1′-piperidinethyl)carbamyl]pyridine (H24), and 2-[N-(2′-pyridylmethyl)carbamyl]-6-[N-(2′-hydroxypropyl)carbamyl]pyridine (H25). Study of possible helicate formation with the unsymmetrical ligands has been initiated, with the ability to form polymetallic species probed by an ESI-MS study.

scholarly journals Intra- and supramolecular interactions incis,mer-diaquatris(1H-imidazole-κN3)(terephthalato-κO)cobalt(II) monohydrate

2012 ◽  
Vol 68 (4) ◽  
pp. m480-m481
Author(s):  
Aouaouche Benkanoun ◽  
Fadila Balegroune ◽  
Achoura Guehria-Laïdoudi ◽  
Slimane Dahaoui ◽  
Claude Lecomte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Membered Ring ◽  
The Other ◽  
Supramolecular Interactions ◽  
Carboxylate Group ◽  
The Third ◽  
Intramolecular Hydrogen ◽  
The Ideal

In the title compound, [Co(C8H4O4)(C3H4N2)3(H2O)2]·H2O, thecisoidangles are in the range 85.59 (5)–93.56 (5)°, while two equaltransoidangles deviate significantly from the ideal linear angle, the third being almost linear. One carboxylate group is almost coplanar [1.23 (13)°] with the plane of its parent aromatic ring, although it has one O-atom donor involved in one coordination and one hydrogen bond as acceptor. The other carboxylate group does not coordinate and is rotated out of this plane with a torsional twist of 17.27 (20)°. The coordination neutral entity, based on aqua ligands and two cyclic co-ligands seems, at first sight, monomeric. Strongly tight,viaone intramolecular hydrogen bond between aqua and carboxylate O atoms, it brings out a quasi-planar six-membered ring around the CoIIatom, turning the CoN3O3coordination octahedron into a new building block. The rigidity of this feature associated with several hydrogen-bonded arrays yields an extended structure. In the resulting supramolecular packing, a binuclear hydrated CoIIassembly, built up from triple strands driven by different heterosynthons, embodies the synergy of coordination, covalent and hydrogen bonds.

scholarly journals Synthesis and Mesomorphic and Electrical Investigations of New Furan Liquid Crystal Derivatives

2021 ◽  
Vol 9 ◽  
Author(s):  
Laila A. Al-Mutabagani ◽  
Latifah A. Alshabanah ◽  
Sobhi M. Gomha ◽  
Tariq Z. Abolibda ◽  
Mohamed Shaban ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Ester Group ◽  
Molecular Structures ◽  
The Other ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
Group A ◽  
Direct Band ◽  
Liquid Crystalline Materials ◽  
Chain Lengths

New homologues set liquid crystalline materials, based on furfural derivatives, namely, (E)-4-((furan-2-ylmethylene)amino)phenyl 4-alkoxybenzoate (Fn), were synthesized and investigated for their mesomorphic and optical characteristics. The prepared homologues series constitutes three derivatives that bear different terminal flexible alkyl chain lengths that vary between 6 and 12 carbons and attached to the phenyl ring linked to the ester group. A furfural moiety is introduced into the other terminal of the molecular structure. Mesomorphic characterizations of the prepared derivatives were measured using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Molecular structures were elucidated via elemental analyses, FTIR, and NMR spectroscopy. DSC and POM showed that all the synthesized furfural derivatives are purely nematogenic, exhibiting an enantiotropic nematic (N) mesophase, except for the longest chain derivative (F12) that is dimorphic possessing a monotropic smectic A phase and an enantiotropic N mesophase. Results indicated that the incorporation of the heterocyclic furfural ring into the molecular skeleton affected both the mesophase range and stability of investigated homologue. Analysis of the optical properties revealed that the shortest chain compound (F6) possesses two direct band gaps, at 2.73 and 3.64 eV, in addition to higher absorption than the higher homologues, F10 and F12. On the other hand, all the synthesized homologues (Fn) showed Ohmic behaviors, with electric resistances in the GΩ range. The values of the electrical resistances are 103.71, 12.91, and 196.85 GΩ at 0.05 V for F6, F10, and F12, respectively.

Tonsillar Inflammation, a Rare Cause of Bradycardia and Hypotension

2018 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Streptococcus Pyogenes ◽  
Fusobacterium Necrophorum ◽  
Outpatient Setting ◽  
Peritonsillar Abscess ◽  
The Other ◽  
Streptococcus Group ◽  
Other Hand ◽  
Group A

Tonsillitis is a frequently encountered pathology in the outpatient setting, usually caused by viruses [1]. When bacterial, the most common causatory microbe is streptococcus group A [1]. Tonsillar and peritonsillar abscess (PTA) on the other hand are never viral, and are usually caused by streptococcus pyogenes, Streptococcus melleri, fusobacterium necrophorum and staphylococci [1,2]. The overall incidence of PTA is suggested to be 37/100,000 patients, with the highest incidence between ages 14-21 at 124/100,000 [3].

Psychophysically Based Physical Capability Limits For Right Angle Power Tool Operation

2020 ◽  
Vol 64 (1) ◽  
pp. 910-914
Author(s):  
Jonathan Valencia ◽  
Joel Cort
Keyword(s):  
Analysis Of Variance ◽  
The Other ◽  
Mixed Design ◽  
Joint Orientation ◽  
Physical Capability ◽  
Subject Variables ◽  
Group A ◽  
Repeated Analysis ◽  
Post Hoc

A psychophysical methodology was utilized to examine 40 non-skilled female participants performing right-angle power tool (RAPT) fastening tasks. A combination of two between subject variables were examined for a total of four between-subject groups: joint orientation (horizontal and vertical planes) and joint hardness (hard and soft joints). Participants were evenly distributed into one of four joint orientation- hardness groups. Within each group, a combination of three fastening strategies and three fastening frequencies were performed by each participant. The chosen target torque determined the physical capability limits (PCL). A mixed-design repeated analysis of variance with Tukey’ significance post hoc test were used to determine any significance with the measured variables ( p<0.05). Fastening strategy and frequency influenced the chosen torque magnitude. Participants chose significantly higher target torques with the Turbo Tight strategy in comparison to the other two strategies. Furthermore, participants chose to accept lower target torques and forces as fastening frequency increased.

scholarly journals Effect of Photofunctionalization with 6 W or 85 W UVC on the Degree of Wettability of RBM Titanium in Relation to the Irradiation Time

2021 ◽  
Vol 11 (12) ◽  
pp. 5427
Author(s):  
Arturo Sanchez-Perez ◽  
Nuria Cano-Millá ◽  
María José Moya Villaescusa ◽  
José María Montoya Carralero ◽  
Carlos Navarro Cuellar
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Irradiation Time ◽  
Contact Angles ◽  
The Other ◽  
Control Group ◽  
Hydrophilic Surface ◽  
Biological Ageing ◽  
Ultraviolet C ◽  
Group A

Photoactivation with ultraviolet C light can reverse the effects derived from biological ageing by restoring a hydrophilic surface. Ten titanium discs were randomly divided into three groups: a control group, a 6 W group, and an 85 W group. A drop of double-distilled, deionized, and sterile 10 µL water was applied to each of the discs. Each disc was immediately photographed in a standardized and perpendicular manner. Measurements were taken based on the irradiation time (15, 30, 60, and 120 min). UVC irradiation improved the control values in both groups. There was no difference in its effect between the 6 W group and the other groups during the first 30 min. However, after 60 min and up to 120 min, 85 W had a significantly stronger effect. The contact angles with the 85 W ultraviolet light source at 60 and 120 min were 19.43° and 31.41°, respectively, whereas the contact angles for the 6 W UVC source were 73.8° and 61.45°. Power proved to be the most important factor, and the best hydrophilicity result was obtained with a power of 85 W for 60 min at a wavelength of 254 nm.

Dirty Work and Dirtier Work: Differences in Countering Physical, Social, and Moral Stigma

2014 ◽  
Vol 10 (1) ◽  
pp. 81-108 ◽  
Author(s):  
Blake E. Ashforth ◽  
Glen E. Kreiner
Keyword(s):  
Distinct Group ◽  
The Other ◽  
Future Research ◽  
Identity Threat ◽  
Dirty Work ◽  
Exotic Dancers ◽  
Organization Level ◽  
Group A

The literature on dirty work has focused on what physically (e.g., garbage collectors), socially (e.g., addiction counsellors), and morally (e.g., exotic dancers) stigmatized occupations have in common, implying that dirty work is a relatively monolithic construct. In this article, we focus on thedifferencesbetween these three forms of dirty work and how occupational members collectively attempt to counter the particular stigma associated with each. We argue that the largest differences are between moral dirty work and the other two forms; if physical and social dirty work tend to be seen as more necessary than evil, then moral dirty work tends to be seen as more evil than necessary. Moral dirty work typically constitutes a graver identity threat to occupational members, fostering greater entitativity (a sense of being a distinct group), a greater reliance on members as social buffers, and a greater use of condemning condemners and organization-level defensive tactics. We develop a series of propositions to formalize our arguments and suggest how this more nuanced approach to studying dirty work can stimulate and inform future research.

Special transport and neurological significance of two amino acids in a configuration conventionally designated as D.

1994 ◽  
Vol 196 (1) ◽  
pp. 297-305 ◽  
Author(s):  
H N Christensen ◽  
A A Greene ◽  
D K Kakuda ◽  
C L MacLeod
Keyword(s):  
Amino Acids ◽  
Receptor Site ◽  
Amino Group ◽  
Carboxylate Group ◽  
Gamma Aminobutyric Acid ◽  
Imino Group ◽  
Group A ◽  
The Central Nervous System ◽  
Lower Homolog ◽  
Alpha Amino Acid

We point out an ability of certain amino acids to be recognized at a biological receptor site as though their amino group bore, instead of an alpha relationship to a carboxylate group, a beta, gamma or delta relationship to the same or a second carboxylate group. For aspartate, the unbalanced position of its amino group between a pair of carboxylates allows its occasional biorecognition as a beta-rather than as an alpha-amino acid, whereas for proline and its homologs, their cyclic arrangement may allow the imino group, without its being replicated, to be sensed analogously as falling at either of two distances from the single carboxylate group. The greater separation might allow proline to be seen as biologically analogous to gamma-aminobutyric acid. This more remote positioning of the imino group would allow the D-form of both amino acids to present its amino group in the orientation characteristic of the natural L-form. The dual modes of recognition should accordingly be signalled by what appears to be low stereospecificity, actually due to a distinction in the enantiorecognition of the two isomers. Competing recognition for transport between their respective D- and L-forms, although it does not prove that phenomenon, has been shown for proline and, significantly, even more strongly for its lower homolog, 2-azetidine carboxylate. Such indications have so far revealed themselves rather inconspicuously for the central nervous system binding of proline, reviewed here as a possible feature of a role suspected for proline in neurotransmission.

scholarly journals Short-term evaluation of an intra-articular technique for cranial cruciate ligament rupture in dogs using nylon or polyester

2018 ◽  
Vol 39 (2) ◽  
pp. 593
Author(s):  
Tiago Carmagnani Prada ◽  
Anderson Coutinho da Silva ◽  
Bruno Watanabe Minto
Keyword(s):  
Cruciate Ligament ◽  
The Other ◽  
Polyester Yarn ◽  
Short Term ◽  
Limb Function ◽  
Cranial Cruciate Ligament ◽  
Ligament Rupture ◽  
Group A ◽  
Group B ◽  
Cranial Cruciate Ligament Rupture

Cranial cruciate ligament rupture (CCrLR) is a common condition found in the small animal routine, being correlated to traumas, obesity, genetic factors, and primary osteoarthritis (OA) in dogs. Affected animals show articular instability that, if not corrected surgically, may cause secondary OA and loss of limb function. The aim of this study was to compare short-term results of the intra-articular technique for knee stabilization after CCrLR using a surgical button associated with polyester yarn (Group A), the surgical button associated with nylon yarn (Group B), and surgical toggle associated with polyester yarn (Group C). Eighteen dogs presenting CCrLR, weight varying from 5 to 35 kg, and different sex and breed were divided into three groups of six individuals. OA radiographic grade, pre- and post-operative lameness, surgical time, and the macroscopic aspect of cartilage were assessed. The intra-articular technique was performed by passing a suture through two tunnels, drilled in the femoral condyle and tibial crest to stabilize the knee joint. Twelve animals presented a decreased lameness and normal limb function after 15 days. On the other hand, four dogs from Group B presented complications: two dogs had suture rupture after 30 days and other two showed muscular contracture with decreased range of motion, followed by loss of limb function. In Group A, one dog showed suture rupture after 15 days and other had suture infection after 30 days. In Group C, dogs recovered normal limb function without complications. Therefore, surgical toggle associated with polyester yarn was better than the other studied materials.

scholarly journals Efficacy of High-Power Laser in Alleviating Pain and Improving Function of Patients With Patellofemoral Pain Syndrome: A Single-Blind Randomized Controlled Trial

2018 ◽  
Vol 10 (1) ◽  
pp. 37-43
Author(s):  
Farshad Nouri ◽  
Seyed Ahmad Raeissadat ◽  
Dariush Eliaspour ◽  
Seyed Mansoor Rayegani ◽  
Maryam Sadat Rahimi ◽  
...  
Keyword(s):  
Controlled Trial ◽  
Pain Syndrome ◽  
The Other ◽  
Short Term ◽  
Randomized Controlled ◽  
Group A ◽  
Laser Group ◽  
Group B ◽  
Single Blind ◽  
Post Therapy

Introduction: In this study, a single-blind and randomized controlled trial (RCT) for assessing the effectiveness of high-power (up to 12 W) laser therapy (HPLT) on patients with patellofemoral pain syndrome (PFPS) was carried out. Methods: Forty-four patients were randomly assigned to two treatment groups by generating random numbers with MATLAB 2014b software, where odd and even numbers were attributed to sham laser group (group A) and actual laser group (group B), respectively. Group B patients underwent HPLT with total dose of 300 J/session for 5 consecutive sessions separated by a 2-day interval. On the other hand, sham laser was applied to group A patients. Both groups had the same exercise therapy programs during the study period (3 months). The exercise therapy program included isometric knee exercise for 3 sets per day and 10 times in each set, with duration of 10 seconds per time and straight leg raise for 15 seconds 10 times a day. The group codes of patients were not revealed to subjects and data analyzer until completion of the study. Kujala, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS) questionnaires were chosen as outcome measures. These questionnaires were completed at three points during the study; at the beginning of the study to obtain the pre-therapy conditions and one month and three months after the start of the study to evaluate post-therapy conditions. Results: Two main analyses were conducted: within-group and between-group analyses. Withingroup analyses indicated significant improvements in respect to all measurements where pretherapy and post-therapy comparisons were conducted in both groups (P < 0.05). On the other hand, between-group comparisons did not reveal any statistically significant functional difference between group A and group B regarding the evaluative criteria (P > 0.05) except for pain VAS (P < 0.05). Conclusion: This study indicated that short-term HPLT accompanied by appropriate exercise regimen significantly decreased pain in patients with PFPS. But it was not recommended as an efficient modality in functional improvement. Also, it was observed that, in the short-term period of study, HPLT was a safe modality.

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