Dört yeni makrosiklik vic dioksimin sentezi ve komplekslerinin incelenmesi

Abstract

Vic-dioksimler geçiş metalleriyle verdikleri stabil kompleksler dolayısıyla şelât teşkil edici ola rak ilgi çekmeye devam etmektedirler. Son yıllarda çeşitli biyolojik mekanizmaların aydınlatılmasında da önem kazanmışlardır. 1967 yılından beri yoğun araş tırmalara konu olan taç eter bileşikleri ise alkali ve toprak alkali metal iyonları ve hatta nötral orga nik moleküllerle kompleks oluşturmaktadırlar. Bu iki özelliği bir arada ihtiva eden çeşitli sayılarda donor atomlara sahip yeni makrosiklik vic~di ok simlerin sen tezini yapmak ve bunların geçiş metalleriyle kompleks lerini incelemek bu çalışmanın amacını teşkil etmiştir. Başlangıç maddesi olarak, 1-5 polietilen glikol zincirine sahip l,w-difenil nitro bileşikleri hazır lanmıştır. Bunun için o-nitro klor benzen ile mono-, di-, tri- veya tetra-etilen glikol doğrudan veya o- nitro fenol ile söz konusu glikollerin tosilatları reaksiyona sokulmuştur. Dinitro bileşiklerinin Sn/HCl veya (SnC^/CH-COOH/HCl) çözeltisi ile indirgenmesin den tekabül eden 1, w-dif enilamino türevleri elde edil miştir. Amin bileşikleri ant i- diklorglioksim ile mut lak metanol içerisinde ve aşırı miktarda NaHCO- kulla narak reaksiyona sokulmuş ve aşağıdaki yeni ligandlar elde edilmiştir: 1- 2,3-Bis(hidroksiimino)-l,4-diaza-7,10-dioksa-(5,6)- (11, 12)dibenzo~siklodeka-5, ll-dien(ODIH? ) 2- 2,3-Bis(hidroksiim.ino)-l,4-diaza-7,10,13-trioksa- (5, 6)-( 14, 15-)di'benzo-siklopentadeka-5, M-dieniOTRHU) IV 3- 2,3-Bis(hidroksiimino)~l,4-diaza-7,10,13,16-tetra- oksa-(5, 6) -(17, 18)dibenzo-siklooktadeka-5, 17-dien (0TEH2) 4- 2, 3-Bis(hidroksiimino)-l,4-diaza-7, 10,13,16, 19- pentaoksa-'(5/6)-(20,21)-dibenzo-sikloheneikoza- 5,20-dien (0PTH2) n- 0,1,2,3 OH OH Bu ligandlarm yapıları H-n.m.r., i.r, ve u.v.- visible spektrumlan ile elementel analiz sonuçlarına göre kesin olarak belirlenmiştir. Kriyoskopik olarak yapılan molekül ağırlığı tayinleri de bu yapıları des teklemiştir. Spektral veriler söz konusu vic-dioksim- lerin ant i- formunda olduğunu göstermektedir. Bu çalışmada sentezi yapılan vic-dioksimlerin makro halka grubunda iki azot ile 2,3,4 veya 5 oksi jen atomu bulunduğundan, bu bileşiklerin alkali komp- V leksleri incelenmiş, fakat halkada bulunan iki azot atomu dolayısıyla stabilite azaldığından kompleksler izole edilememiştir. Ancak halka yapısının oluştuğunu ispatlayan pikrat testi olumlu sonuç vermiştir, ODIH2/ OTRH2, OTEH2 ve OPTH2 ligandları Cu(II), Ni(II) ve Co(II) ile 1:2 metal/ligand oranında kare düzlemsel kompleksler vermişlerdir, Cd(II) ve Zn(II) komplekslerinde ise her metal iyonu bir vic-dioksim molekülündeki N atomları üzerinden koordinasyona gir miş, ayrıca iki hidroksil iyonu da metale bağlanmıştır Dimerik yapıdaki uranil kompleksinde de metal/li gand oranı 1:1 dir, fakat iki uranil iyonu arasında iki OH grubu köprü görevi yapmaktadır. Bu komplekslerin yapıları elementel analiz, i.r, ve u.v. -visible spektral verileri ile aydınlatılmaya çalışılmıştır.

The interesting structures of the transition me tal complexes of diaminoglyoxime reported in the previous papers oriented our researches to the new derivatives of diaminoglyoxime. For this purpose, anti-dichloroglyoxime is an efficient reactant. It reacts with the compounds containing -NH groups by elimination of HCI. As a bifunctional reactant, anti- dichloroglyoxime is also useful in the syntheses of cyclic compounds. In two early works, two new cyclic compounds, namely 1, 4-diphenyl-2, 3-bis( hydroxyimino) -piperazine and 1, 3-diphenyl-2-thioxo-4, 5-bis( hydroxyimino) -'imi dazoline were obtained in anti- and amphi- forms through the reaction of N,N ' -diphenyl-ethy lenediamine and diphenylthiourea with cyanogen-di-N-oxide, which was prepared from anti-dichloroglyoxime and Na^CO-, Substituted mono- and diaminoglyoximes have been also prepared from mono- and di-chloroglyoxime and various amines. In this thesis, we describe the syntheses of four new macrocyclic dioximes derived from the reac tion of anti-dichloroglyoxime and 1, co-diphenylamino compounds containing 1-4 polyethy lenegly col groups on the chain in order to investigate the effect of the macrocyclic ether groups on the isomerism and complex formation of the vic-dioximes. Cu(II), Ni(II), Co(II), Cd(II), Zn(II), U02(VI) complexes of these dioximes are described and their structures are com pared with the previously reported complexes of various VII vic-dioximes. The condensation reactions between 1, u)-diamin.o compounds and anti-dichloroglyoxime are essentially untemplated. Solid NaHCO- in excess is added during the reaction in order to neutralize HC1 formed. Since strong bases such as Na2C0~ causes the elimination of HC1 from anti-dichloroglyoxime and the formation of a very unstable compound, cyanogen-di-N-oxide, NaHCO~ is suitable for this reaction as a buffer. For the cyclization step, the bulky phenyl groups at the end of the polyethylene chains should direct ~NHU groups into the proper positions. The H-n.m.r. and i.r. spectra of these vic-dioxj- mes are in harmony with the spectra of diaminoglyoxime and related compounds. The OH and NH protons are easily identified in the H-n.m.r. spectra around 10,30-10.50 ppm and 7.50-7.60 ppm, respectively. These singlets disappear on D"0 exchange. The multiplets at 7.20- 6.60 and the singlets around 3.60-3.76 are assigned to aromatic and aliphathic (-CH^-O) protonsy respec tively. The characteristic i.r. and H-n.m.r, data of these compounds, also support the proposed macrocyclic structures. The stereoisomeric forms of these macrocyclic vic-dioximes can be assigned according to the spectral data and their ability to form metal complexes. Since the syn-dioximes are unable to form metal complexes, the syn form is impossible for the vic-dioximes prepa red in this work. H-n.m.r. data show single chemical shift around 10.30-10.40 ppm for OH protons; these VIII singlets are strong evidences for anti-f rom in all vic-dioxiroes. Intramolecular hydrogen bonding in one of the oxime groups of amphi-dioxime would cause two different peaks for two oxime protons. V(0H) vibrati ons of ODIH2, OTRHL, OTEhL, and OPTH2 are around 3220- 3250 cm and these values are suitable for anti-form. Consequently, for all these four macrocyclic dioximes, an anti-structure is proposed. The macrocyclic compounds prepared during, this work contain 2 nitrogen and 2,3,4, or 5 oxygen atoms as donor groups. The interaction of these compounds with alkali metal ions are also investigated, but al kali metal complexes could not be isolated. The potasi- um picrate test shows the presence of some interaction when especially OTErL or 0PTH« is added into tube con taining aqueous potasium picrate solution on chloro form layer. This weak complexation is just as expected, since the stability constans of alkali metal-macrocycle complexes falls in the order of 0>NR>NH>S as bonding sites, Three types of complexes have been isolated from ODIH2, OTRH2, 0TEH2, 0PTH2 and Ni(II), Cu( I I ), Co( II ), U02(VI), Cd(II), and Zn(II) salts. In these complexes the transition metal ions are coordinated to the oxime groups and unlike 2,3-bis hydroxyimino-i, 4, 7, 10-tetra- aza-(5, 6)- ( 11, 12)-dibenzo-cyclododeca - 5,11-diene which forms three nuclear complexes with a metal-ligand ra tio of 3:2, none of the transition metal ions have been trapped in the macrocyclic rings. Therefore, it might be concluded that the macrocylic compounds which have two vic-aza groups and 2,3,4, or 5 oxygen atoms IX as donor sites with ethylene bridges in between do not have appropriate steric structure for complex formation. Cu( 1 1 )-Ni( 1 1 )- and Co( 1 1 )- complexes of the vic- dioximes are square-planar and have a metal-ligand ratio of 1:2. This usual structure for ant i-dioximes is based on the formation of 2 (0-H-O) bonds for each molecule. The weak deformation vibrationsof this hydro gen bridges are observed around 1720-1725 cm for all Ni(II)/ Co(II), and Cu(II) complexes. The insolubility of the dimethylglyoxime complex of Ni(II) is due to metal-metal bonded polymeric structure,. In contrast to' Ni (Hdmg) «, Ni(II) complexes of these four macro- cyclic dioximes are slightly solube in chloroform and in methanol. This is appearently due to the bulky aza- ether group which prevents the interaction of metal ions. In the Cd(II) and Zn(II) complexes of vic-diox- imes, two of the four coordination sites of metal ions are occupied by two nitrogen atoms of the dioxime mo lecule; the other two groups are either halogens or hydroxyl ions according to the reaction conditions. 0DIH2/ 0TRH2, 0TEH2 and 0PTH2 complex with Cd(II), Zn(II) in a ratio of 1:1. The complexes do not have any halo gen ions. The i.r. spectra indicates that v^OH) vibra tions are present as in the ligands. The C=N absorp tions (1620 cm ) are slightly lowered compared to those of the vic-dioximes (1635-1640 cm ) and are consistent with the NN-chelate coordination. The uranyl(VI) complexes of all for vic-dioximes precipitate immediately even without any additions of a base. The uranyl-dimethy 1 glyoxime complexes have X been studied in solution and 1:1 metal-ligand ratio has been found both in potentiometric titration and spectrophotometry methods. In a recent work, H-n.m.r spectrum of the uranyl complex of N,N ' -bis(4 ' -benzo [ 15-crown-5] )diaminoglyoxime have been investigated and a dimeric structure with two OH bridges have been found. Elemental analytical results closely indicate similar dimeric compounds for the uranyl complexes of ODIH2, OTRH2, OtEH2, and OPTHr In the i.r. spectra of the complexes, a strong band around 905 cm is the characteristic frequency for v(0=U=0) vibrations. The four new macrocyclic vic-dioximes prepared in this work are as follows: 1) 2r3-Bis(hyd r ox yimino) -l,4-diaza-7,10-di oxa-( 5,6) - (ll/lZydibenzo-cyclodeca-^ll-dienefODIH^). 2) 2, 3-Bis(hydroxyimino) -1, 4-diaza-7, 10, 13-trioxa- (5, 6 ) - ( 14, 15)dibenzo-cyclopentadeca-5, 14-diene (OTRH2). 3) 2,3-Bis(hydroxyimino)-l,4-diaza-7,10,13,16-tetraoxa- (5, 6)- ( 17, 18)dibenzo~cyclooctadeca-5, 17-diene(0TEH2). 4) 2,3-Bis(hydroxyimino)-l,4-diaza-7,10,13,l^,19-penta- oxa^(5,6)-(20,21)-dibenzo-cycloheneicosa-5,20~diene (OPTH2). Cu(II), Ni(II), Co(II), Cd(ll), Zn(II), and U02(VI) complexes of all four vic-dioximes have been also iso lated.