Abstract The permittivities and dielectric losses of 2-Piperedone, -Caprolactam, 2-Azacyclooctanone and 2-Azacyclononanone have been studied in chloroform solutions. They have been measured using Q meter at frequency range 150KHz to 15MHz.Both 2-Piperedone and -Caprolactam solutions were studied at concentration range 0.05 to 0.25M and over temperatures range of -10 to 45 and. The dielectric studies of 2-Azacyclooctanone solutions cover a concentration range 0.05 to 0.125M and over temperature range of -10 to 45, while that of 2-Azacyclononanone solutions were studied at concentration range 0.01 to 0.075M and over temperature range of -10 to 45. The permittivities at higher concentrated solutions up to 1.5M of 2-Pipere-done, -Caprolactam and 2-Azacyclononanone were also measured at 2MHz using dipole meter DM01 over the temperature rang -10 to 45.The static permittivities for the four systems were discussed as the affect concentration, temperature and the number of CH2 group in the cyclic amides. All show normal behaviour except that the CH2 does not show clear affect. Single relaxation process were observed for the studied compound in the chloroform solutions ( =10-9 sec). All cases, the presence of a relaxation process was established at frequencies higher than used here. These relaxation processes were discussed in terms of their relation to concentration and the number of CH2 group. The dielectric activation energies were calculated using Eyring equation. The obtained values were discussed also in terms of concentration affect. A dependence of on concentration was observed. The dipole moments for the four studied compounds in solutions were evaluated using of Cole-Cole a semicircle plots, which considered to be associated with the relaxation process and other dipole moments were evaluated using =. This was assigned as an apparent dipole moment. All these dipole moments were discussed in terms of concentration and temperature affect. The obtained dipole moments in all studied case were much larger than those expected for planer dimers association. So they assigned to the presence of dimers and trimer or tetramers association in the studied solutions.Kirkwood correlation factor for the studied systems were calculated and discussed as a function of concentration. All values of g are less than unity and were assigned to a cyclic association form.
لطفية صادق حسن المجدوب (2010)

في هذه الدراسة ثم تحضير ثلاث متصلات مختلفة: 1- ذات نظام حلقي كبير (1,4,7,10 tetraaza 2,3,8,9 tetra phenyl tetraocta,1,3,7,9 diene) 2- ذات نظام متبادل ligand tetradentate conjugated benzidine)” acetylacetonato)- bis) - ذات نظام شبه حلقي مفتوح ligand macrocycle open ” ethylendiamin) acetylacetonato))( bis كما تم تحضير المركبات التناسقية MLn لكل من المتصلات السابقة مع 2+M= 2+ Co , 2+ Cu Zn 2+ و المقارنة بينها من حيث التركيب و النشاط الحيوي و السلوك الكهروكيميائي وتبرز أهمية هذه المركبات التناسقية " ذات النظام الحلقي الكبير" من خلال نشاطها الحيوي المشابه لتلك الأنظمة الحيوية الموجودة في جسم الإنسان، ودورها في العديد من المجالات الحيوية و الطبية والصناعية .ولإيجاد الصيغة الأولية و التركيب الهندسي لهذه المركبات التناسقية تمت دراستها بطرق التحليل الفيزيائية و منها : درجة الانصهار m.p0C وتراوحت بين oC300 > 107 والموصلية EC والذوبانية S والتحليل العنصري CHN والتحاليل الطيفية مثل طيف الاشعة تحت الحمراء FT-IR وطيف الرنين المغناطيسي 1H-13C NMR . ومن خلال التحاليل أمكن الوصول إلى النتائج الآتية -تدل قيم درجات الانصهار المتوسطة على أن كل المركبات التي تم تحضيرها يغلب عليها طابع التساهمية و ليست مركبات أيونية -تدل نتائج اختبار الذ وبانية في المذيبات المعروفة منها) (DMSO, DMF, Chloroform,..Methanol على الطبيعة غيرألكتروليتية لها , كما وجد أن معظمها يذوب في DMSO وتقل ذوبا نيتها في المذيبات الأخرى. - ومن خلال القيم المنخفضة لموصلية هذه المواد و التي تتراوح (47-11 Ohm-1cm2.mol-1) ، على أنها غير ألكتروليتية مما يدعم السلوك التساهمي و التناسقي بين الذرات المانحة في المتصلات و ذرة الفلز - ومن خلال دراسة التحليل العنصري للمركبات, أظهرت النتائج تطابقاً كبيراً بين قيم النسبة النظرية والعملية للعناصر C%,H%,N% ، وذلك بما يتوافق مع الصيغ الأولية و التراكيب الهندسية المقترحة للمركبات التي تم تحضيرها.- من نتائج طيف الأشعة تحت الحمراء(4000-600cm-1), ويلاحظ حدوث إزاحة في قيمة الامتصاص عند ارتباط المتصلة بأيون الفلز لتكوين روابط تناسقية (1500-1600cm-1) بالارتباط بذرة النيتروجين لمجموعة الازوميثين((-C=N-, وكذلك (cm-11200-1300) بالارتباط بذرة الأوكسجين لمجموعة -C-O-) ) و يمكن تفسير هذه الإزاحة بسحب للإلكترونات من المتصلة وحدوث الترابط الارجاعي من طرف الفلز مما يسبب ضعفا لبعض الروابط - ومن خلال دراسة نتائج طيف الرنين المغناطيسي NMR ,يتضح الارتباط التساهمي للمتصلات مع أيون الفلز وذلك بالمقارنة بين طيف المتصلة و طيف الفلز. اتضحت إزاحة قمم معينة1H NMR proton ( 7-8ppm); and 13C NMR -C=N ( 150- 170ppm) إلى مواقع أخرى نتيجة لارتباط المتصلة بالفلز. - ولدراسة السلوك الكهروكيميائي للمركبات المحضرة تم استخدام الطريقة الكهروكيميائية CV وذلك لإيجاد جهد الاختزال و الأكسدةRedox Couple و علاقتها بالسلوك الحيوي لهذه المركبات.ويمكن ملاحظة أن جهد الاختزال للفلز يقل عند ارتباطه بالمتصلة المانحة و هذا يزيد من نشاطه الحيوي المتوقع. - وتمت أيضا ًدراسة السلوك الحيوي للمركبات المحضرة وإمكانية استخدامها كمضادات لنمو البكتريا. حيث أظهرت معظمها القدرة علي تثبيط نمو أنواع معينة من البكتريا ومنها Staphylococcus aureus و Escherichia coli حيث بلغت درجة الممانعة "مم 16-10" بالنسبة للمادة القياسية المستعملة الفينول "مم 30-28 " . ومن خلال مقارنة النتائج نلاحظ إن المركب التناسقي يعطي أكثر تثبيطا للبكتيريا مقارنةً بالمتصلة. كما إن النحاس يعطي أفضل درجة ممانعة . ويتدرج النشاط البيولوجي في الزيادة حسب الترتيب الأتي :(+2Cu < < Co2+ +2 Zn). Abstract In this study, three different Schiff bases were prepared: 1- (L1) : macrocycle ligand (1,4,7,10 tetraaza 2,3,8,9 tetra phenyl tetraocta,1,3,7,9 diene macrocycle).2- (H2L2) : conjugated tetradentate ligand (bis(acetylacetonato) 4,4'benzidine(.3- (H2L3) : open macrocycle ligand (bis(acetylacetonato) ethylendiamine(.The metal complexes of these ligands “MLn “ where “M2+= Co+2 ,Cu+2 ,Zn+2 “ were prepared by direct reaction of metal with ligands L1 ,H2L2 ,H2L3. This study is an attempt to prepare macrocycle metal complexes and other ligand metal complexes, which are potentially biologically active similar to those in the biological systems, and to compare these complexes characters with each other and with corresponding molecules in the biological systems. These complexes were synthesized and characterized by several physical methods: melting point (mp .oC ), solubility(S), electric conductivity(EC), elemental analysis (C H N), FT-IR spectroscopy, 1H NMR and 13C NMR spectrometer . - Melting point: the moderate values of the melting points (107 oC< 300 oC ) indicate that all of these compounds have a covalent (coordinative) nature , and are not ionic compounds. -In addition to that the solubility test of these complexes, in suitable solvents ,shows that most of the complexes are slightly soluble in common organic solvents (DMSO,DMF, Chloroform and) methanol.But most of them show maximum solubility in DMSO at room temperature, this indicates that all of these compounds have a covalent nature. -Molar conductance measurements show low molar conductance (11 – 47 S cm2 mol-1) which indicate that the complexes are non electrolytes. These results support the coordination behavior for these complexes. - Elemental analysis (C H N) shows a close coincidence between the experimental values and the theoretical values of %C,%H and %N which were calculated according to the proposed structures. -FT-IR spectra(4000-600cm-1) manifest the coordination of the ligands to the metal ion through the azomethine nitrogen (-C=N-) (1500-1700cm-1) and the oxygen atom of the (-C–O-) (1200-1300) . -1H NMR and 13C NMR spectra showed peaks which are characteristic to the aromatic ligands , ”aromatic” 1H NMR proton ( 7- 8ppm) and 13C NMR -C=N ( 150- 170ppm) are shifted to different field on complexation with metal . This manifests coordination of the ligands to metal ion. -The electrochemical behavior: the complexes were extensively investigated by electrochemical method using cyclic voltammetry (CV) to find a correlation between the redox potential and the antimicrobial activity of these complexes, a lower redox potential enhances higher biological activity. - Antimicrobial screening: the synthesized compounds have been screened against some microorganisms Escherichia coli (gram negative ), Staphylococcus aureus (gram positive), with the help of ‘using cup – cut diffusion method. The inhibition zone range between (11-16mm) against phenol as positive standard(28-30mm) and DMSO as negative control: The activity data show that , the metal complexes to be more potent antibacterial than the parent Schiff base ligand against the tested bacterial species. Also, copper complexes show the best antimicrobial activity against the tested microorganisms, and the biological activity of the complexes increases in this order :( Cu+2 > Co+2 > Zn+2 ).
سهيلة إبراهيم بالقاسم كارة (2013)

The ever-increasing demand for natural products and biotechnology, derived from bees and ultramodernization of various analytical devices, has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. This study aimed to prepare, characterize and examine the stability and evaluation of the antioxidant and the antibacterial activity of Libyan propolis. Propolis Nanoparticles PNP were prepared using particle size reduction, then Transmission Electron Microscope (TEM) at a magnification of X 25000, was used for accurate evaluation of the size distribution of NPs. Three different concentration (10, 5, 2.5 mg/ml) of propolis and nano-propolis powder were tested for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. The quantitative antioxidant activity test results using UV Spectrophotometer absorbance at 517 nm. The antibacterial activities of propolis and prepared nano propolis at different concentrations (10, 5 and 2.5mg/ml) were tested on bacterial strain, Klebsiella, human mouth, skin, and surface bacteria using cup cut diffusion method. The findings exhibited that the prepared propolis Nanoparticles (PNPs) were generally non-spherical with a size 100-200 nm. The PNP was a nano-sized particle around 316 nm in diameter. Zeta potential of PNP showed a negative surface charge value (− 48 mV) which was sufficiently high to avoid NPs aggregation. This value represents a stable and dispersed suspension of NPs and disables the tendency of aggregations in a short in period of time. Poly dispersity index (PdI) of synthetized PNP was used as a measurement of the size distribution. PdI values for PrNP were generally uniform with PdI 0.3 indicating monodispersity of the prepared systems. The propolis and PNPs displayed good antioxidant activity with inhibition percentage (77%, 46% and 18%) for propolis and (82%, 66% and 37%) for PNPs. Propolis nanoparticles showed to have more antibacterial effect compared to propolis. Libyan propolis nanoparticles has shown to be potential candidates as antioxidant and antibacterial agent.
sakina Salem Saadawi, Rabia O Alghazeer, Hanin N. Mughrbi, Bushra M. Dakhil, Rokaya O. Amara, Khairi A. Alennabi, Riham M. El-Moslemany, Khadija O. Turkman, Masarra A. Daraweel(3-2022)