Bazı acesülfam-geçici metal komplekslerinin sentezi, yapısı, spektroskopik, termik ve kromotropik özellikleri
Synthesis, spectroscopic, thermal and chromotropic properties of some acesulfame-transition metal complexes
Yazar: NAZİYE ÇETİN
Danışman: DOÇ. DR. HASAN İÇBUDAK
Ondokuz Mayıs Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı
Derece: Yüksek Lisans, 2005
Konu: Kimya = Chemistry

Özet:
iBAZI ACESÜLFAM-GEÇ METAL KOMPLEKSLER N N SENTEZ , YAPISI,SPEKTROSKOP K, TERM K VE KROMOTROP K ÖZELL KLERÖZETBu tez çal mas nda, ilk defa acesülfam n Mn(II), Co(II), Ni(II), Cu(II), Zn(II)ve Cd(II) kompleksleri sentez edildi. Sentez edilen kompleksler elementel analiz,manyetik duyarl l k, UV-Vis. spektroskopisi, FT-IR spektroskopisi, x- n tek kristalk r n m yöntemi ve kütle spektroskopisi ile karakterize edildi. Komplekslerin termiközellikleri ise e zamanl TG-DTG ve DTA teknikleriyle ayd nlat ld . min azotu,karbonil oksijeni, sülfonil oksijenleri ve halka oksijeni gibi verici atomlara sahip olanacesülfamat ligant n n koordinasyon davran lar belirlendi.Sentez edilen komplekslerin [M(acs)2(H2O)4] (M: Mn(II), Co(II), Ni(II) veCu(II)) ve [M(acs)2(H2O)2] (M: Zn(II) ve Cd(II)) genel formülüne sahip olduklarbulundu. Komplekslerin manyetik moment de>erleri, manyetik duyarl k ölçümlerindenhesapland . Manyetik moment de>erlerine göre Mn(II), Co(II), Ni(II) ve Cu(II)komplekslerinin paramanyetik, Zn(II) ve Cd(II) komplekslerinin ise diyamanyetikolduklar gözlendi. Tüm metal-acesülfam komplekslerinin zay f alan kompleksi; Mn(II)ve Co(II) komplekslerinin yüksek spin kompleksi ve acesülfamat iyonunun zay f birligant oldu>u belirlendi.Acesülfam-metal komplekslerinin yap sal çal malar için önemli olankarakteristik (OH), (C=O), as(SO2) ve (SO2) titre imleri belirlendi. Potasyumsacesülfamda 1661 cm-1'de görünen karbonil gerilme titre iminin komplekslerdek rm z ya kayd > gözlendi. Metal acesülfam komplekslerini FT-IR spektrumlar nda3500-3300 cm-1 aral > nda gözlenen akua ligantlar na ili kin O-H gerilme titre imbantlar n n hidrojen ba>lar ndan dolay geni ledi>i ve k rm z ya kayd > gözlendi.[Co(acs)2(H2O)4] ve [Ni(acs)2(H2O)4] komplekslerinin yap lar x- nlar tekkristal k r n m yöntemiyle belirlendi. Acesülfamat iyonu Co(II) kompleksinde tek di liN-verici bir ligant, Ni(II) kompleksinde ise tek di li O-verici bir ligant olarak davrand .Her iki kompleks de bozulmu oktahedral geometriye sahiptir.Bir örnek olmas aç s ndan, [Co(acs)2(H2O)4] kompleksinin termik bozunmamekanizmas termik analiz teknikleri (TG, DTG and DTA) ve kütle spektroskopisiyleçal ld . Bozunma süreci ile iyonla ma süreci aras ndaki ili ki tart ld .iiKomplekslerin statik hava atmosferindeki termik davran lar ara t r ld . Ni(II)ve Cd(II) kompleksleri s ras yla 71 ºC'de, 72 ºC'de endotermik faz geçi i gösterdi.Tüm metal-acesülfam komplekslerinin ilk bozunma a amas deakuasyondur.Deakuasyon süreci Mn(II), Co(II) ve Cu(II) komplekslerinde iki basamakta, Ni(II),Zn(II) ve Cd(II) komplekslerinde ise tek basamakta gerçekle mektedir. DeakuasyonuSO2 ç k yla acesülfamat ligant n n bozunmas takip etmektedir. K smi bozunmalarsonucu olu an organik kal nt 450 ºC civar nda yanmaktad r. DTGmak dikkateal nd > nda komplekslerin termik kararl l klar : Cu(II) (54ºC)< Mn(II) (85ºC)< Co(II)(118ºC)< Zn(II) (125ºC)< Cd(II) (135ºC)< Ni(II) (150ºC) eklinde artmaktad r. Sonbozunma ürünleri kar l k gelen metal oksitlerdir.Sentez edilen komplekslerin termokromik, solvatokromik ve iyonokromiközellikleri termik analiz ve spektroskopik tekniklerle incelendi. Co(II) ve Cu(II)kompleksleri koordinasyon say s ve ligant alan kuvveti de>i imine ba>l olarak tersinirtermokromizm göstermektedir. Ni(II) kompleksi ise hem faz geçi i, hem dekoordinasyon say s de>i imine ba>l olarak iki farkl tersinir termokromizmgöstermektedir. Ayr ca Co(II) ve Cu(II) komplekslerinin solvatokromik ve iyonokromiketki gösterdikleri bulundu.Anahtar Kelimeler: Acesülfam metal kompleksleri, Termokromizm, Solvatokromizm,Termik analiz, X- nlar .

Abstract:
iiiSYNTHESIS, SPECTROSCOPIC, THERMAL AND CHROMOTROPICPROPERTIES OF SOME ACESULFAME-TRANSITION METALCOMPLEXESABSTRACTIn this thesis, the first acesulfame-metal complexes of Mn(II), Co(II), Ni(II),Cu(II), Zn(II) and Cd(II) have been synthesized. The synthesized acesulfame-metalcomplexes were characterized by elemental analysis, magnetic susceptibility, UV-Vis.spectroscopy, IR spectroscopy, mass spectroscopy and single crystal x-ray diffractionmethod. The thermal behaviors of the acesulfame-metal complexes were also studied bysimultaneous TG, DTG and DTA techniques in static air atmosphere. The coordinationbehavior of acesulfamate as a ligand which has several potential donor atoms i.e. iminonitrogen, carbonyl oxygen, ring oxygen, sulphonyl oxygens has been determined.General formula of the synthesized complexes is found to be [M(acs)2(H2O)4](M: Mn(II), Co(II), Ni(II) and Cu(II)) and [M(acs)2(H2O)2] (M: Zn(II) and Cd(II)). Themagnetic moment values of the acesulfame-metal complexes have been calculated fromthe magnetic susceptibility measurements. According to the magnetic moment values ofthe Mn(II), Co(II), Ni(II) and Cu(II) complexes are seen to be paramagnetic, whereasthe Zn(II) and Cd(II) complexes are found to be diamagnetic. The observed magneticmoment values indicate that all the acesulfame-metal complexes are weak fieldcomplexes; the Mn(II) and Co(II) complexes are of high spin type and acesulfamate ionis a weak ligand.The characteristic IR bands of (OH), (C=O), as(SO2) and sym(SO2) of themetal-acesulfame complexes have been determined found that the most important forthe structural studied. The carbonyl stretching band of potassium acesulfame observedat 1661 cm-1 was shifted to lower wavenumber in the spectra of the acesulfame-metalcomplexes. The broad and red-shifted O-H stretching bands observed in 3500-3300 cm-1interval indicate hydrogen bonding of the aqua ligands.The crystal structure of [Co(acs)2(H2O)4] and [Ni(acs)2(H2O)4] complexes weredetermined by x-ray single crystal method. The acesulfamate ligand acts as amonodentate O-donor ligand in [Ni(acs)2(H2O)4] complex, whereas N-donor ligand in[Co(acs)2(H2O)4] complex. Both complexes have pseudo-octahedral geometries.ivAs an example, the thermal decomposition pathway of [Co(acs)2(H2O)4]complex has been studied by thermal analysis (TG, DTG and DTA) and massspectroscopic techniques. The relation between the thermal and ionization process hasbeen discussed.The thermal behaviors of the acesulfame-metal complexes have beeninvestigated in the static air atmosphere. The Ni(II) and Cd(II) complexes exhibitendothermic phase transition at 71 and 72 ºC, respectively. The first decompositionstage is deaquation for all the acesulfame-metal complexes. The thermal deaquation ofthe Mn(II), Co(II) and Cu(II) complexes occurred in two steps, but the thermaldeaquation of the Ni(II), Zn(II) and Cd(II) complexes occurred in one step. The thermaldecomposition of acesulfamate ligand in the metal complexes proceeds by initial releaseof SO2. The organic residue formed partial decomposition burns at ca. 450 ºC. Thesequence of thermal stabilities of complexes has been determined by using the DTGmakvalues: Cu(II) (54ºC)< Mn(II) (85ºC)< Co(II) (118ºC)< Zn(II) (125ºC)< Cd(II)(135ºC)< Ni(II) (150ºC). The final decomposition products of the acesulfame-metalcomplexes found to be the respective metal oxides.The thermochromic, solvatochromic and ionochromic properties of thesynthesized acesulfame-metal complexes have been studied by thermal andspectroscopic techniques. The Co(II) and Cu(II) complexes show reversible continuousthermochromism depending on change of the coordination number and ligand fieldstrength. The Ni(II) complex indicate two different thermochromism depending onphase transition (reversible) and changing of coordination number. The Co(II) andCu(II) complexes also exhibit solvatochromic an ionochromic property.Key Words: Acesulfame-metal complexes, Thermochromisim, Solvatochromizm,Thermal analysis, X-ray.