This study has three parts, the first one is the synthesis of a novel Schiff bases by the condensation of guanine or 9-[{2-hydroxyethoxy}methyl]-9H-guanine with variety aldehydes to yield four different bases as follows: (E)-2-((4-nitrobenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S1), (E)-2-((4-methoxybenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S2), (E)-2-((2-hydroxybenzylidene) amino)-9-((2-hydroxy ethoxy)methyl)-1,9-dihydro-6H-purin-6-one (S3), and (E)-2-(((9-((2-hydroxy ethoxy)methyl)-6-oxo-6,9-dihydro-1H-purin-2-yl)imino)methyl)benzoic acid (S4). Then, spectroscopic analyses such as Elemental Analysis, UV/VIS, Mass spectra, FTIR, 1H,13C-NMR were made to recognize these bases. In the second part, the ability of synthesized bases to undergo a charge transfer reaction was examined in an ethanolic solution at 28℃ with Iodine (I2) and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acceptors. The nonbonding interactions were studied using Benesi–Hildebrand method to estimate the stability parameters for all formed charge transfer complexes. The results of CT-energies and Gibbs free energies (ΔG˚) confirmed the stability of these complexes, and all complexes follow the Benesi–Hildebrand equation. The results showed that the DDQ-complexes have an affinity constant ranging from (916.6–24,400) mol−1.L higher than the affinity constant of I2-complexes which ranges from (428.5–7000) mol−1.L. Moreover, the KCT of S2 > S1 and KCT of S4 > S3 were as follows [1222.2 for S1-I2, 4333.3 for S1-DDQ, 2812.5 for S2-I2, 4800 for S2-DDQ] and [3809.5 for S3-I2, 12,200 for S3-DDQ, 7000 for S4-I2, 24,400 for S4-DDQ] due to the specific properties of each compound. The direct energy gap (Egdir) of each complex was also obtained by applying Tauc's method. Iodine complexes with S1, S2, S3, S4, as well as S1-DDQ displayed energy gaps equal to (5.14, 5.11, 4.61, 4.51, and 3.90) eV, respectively, and are likely to act as insulators. In contrast, the DDQ complexes of (S2/S3/S4) bases exhibited Egdir values at (2.85–2.24) electron volts which makes them suitable for semiconductor material usage. Finally, the third part of this work included a theoretical study using DFT/B3LYP/3-21G method to illustrate and prove the experimental findings, which were consistent with the theoretical results.
ABSTRACT Background: Dental anomalies of teeth are major issue that contributes to dental problems encountered in general practice. The aim of this study is to measure the prevalence of dental anomalies and the associated etiological factors among 15 years old students in Basrah city –Iraq. Materials and methods: The total sample composed of 1000 students (435 males and 565 females) from urban area selected randomly from different high schools in the city. Diagnosis of dental anomalies were recorded by present or absent, diagnosis and recording of enamel defects were done according to the criteria of WHO (1997). Results: The prevalence of hypodontia was 4.6%, Females have higher prevalence than males (5.8% females and 3.0% males), ta
... Show MoreDeconstructionism opened the door wide to multiple readings and restore the reader his authority that he lost in the modernism, thus became more able to decipher the plastic discourse through reconstruction according to what he wants or what the plastic discourse gives him of possibilities beyond consumerism and thus the author has been canceled. The problem of the current research is limited to the following question: does deconstructionism in postmodern arts have a role in teaching the artistic tasting for the learner? The aim of the current research is to reveal the deconstruction work mechanisms in postmodern arts and their role in teaching the artistic tasting for the learner. As for the theoretical framework, the first section focu
... Show MoreThe research aims to Applied Study in the nature of the impact of information asymmetry for brokerage firms in the common stock trading, The research included the theoretical concepts associated with each of the brokerage firms ,information asymmetry and common stock trading, It used the financial methods on the practical side of the information asymmetry for brokerage firms based in the sector as well as trading volume and spread for common stock , The community of the research included the Iraq Stock Exchange,the sample of research the companies listed which have been trading on its stock for the period August 2015 until December 2015 as well as brokerage firms
amounting to 47 brokerage firm. The resea
... Show MoreObjective: To identification environmental and psychological violence's components among collegians’ students of different stages, and gender throughout creating specific questionnaire, and estimating regression of environmental domain effect on psychological domain, as well as measuring powerful of the association contingency between violence's domains in admixed form with respondent characteristics, such that (Demographics, Economics, and Behaviors), and extracting model of estimates impact of studied domains in studying risks, and protective factors among collegians’ students in Baghdad city. Methodolog
Background: Calcium hydroxide and calcium-silicate materials used as direct pulp capping materials. The aims of this in vitro study is to compare among these materials in, the calcium ion release and pH change in soaking water after immersion of materials’ specimens in deionized water. Also Solubility and water sorption of materials’ specimens measured after soaking time. Calcium-silicate materials used were Biodentine, TheraCal and MTA Plus. Materials and methods: Four materials used in this study; Urbical lining (as control group), Biodentine, TheraCal and MTA Plus. Ten discs fabricated from each tested material, by using plastic moulds of 9 mm diameter and 1 mm thickness. Each specimen was immersed in 10 ml of d
... Show MoreПредметом нашего исследования является вводные слова и их значения в современном русском языке. И прежде чем углубиться в нашу научную работу нам было необходимо определить понятие вводных слов и их функция и место в системе русского языка. По словам В. Г. Лебедева и Л. С. Тюревы "Вводные слова вводятся в предложении, чтобы выражать отношение говорящего к высказываемой мысли, оценки ее содержа
... Show MorePseudomonas aeruginosa is a common and major opportunistic human pathogen, its causes many and dangersinfectious diseases due to death in some timesex: cystic fibrosis , wounds inflammation , burns inflammation , urinary tract infection , other many infections otitis external , Endocarditis , nosocomial infection and also causes other blood infections (Bacteremia). thereforebecomes founding fast and exact identification of P. aeruginosafrom samples culture very important.However, identification of this species may be problematic due to the marked phenotypic variabilitydemonstrated by samples isolates and the presence of other closely related species. To facilitate species identification, we used 16S ribosomal DNA(rRNA) sequence data
... Show MoreSmoking and central obesity have both been linked to periodontitis, but their combined relationship with periodontal disease may be influenced by demographic and behavioral factors. This cross-sectional study analyzed records of 420 adult dental patients attending the College of Dentistry at the University of Baghdad. Data included demographic characteristics, smoking status, periodontal clinical findings, body mass index (BMI), and waist-to-height ratio (WHtR). Periodontitis was defined according to the 2018 classification framework, and logistic regression models were used to examine the associations of smoking and obesity-related indicators with periodontitis. The overall prevalence of periodontitis was 36.4%. Participants with p
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