magistrsko delo
Klemen Cotman (Author), Bojan Kozlevčar (Mentor), Franc Požgan (Thesis defence commission member), Andrej Pevec (Thesis defence commission member)

Abstract

Pripravili smo šest koordinacijskih spojin z vezano citronsko kislino (H4L = C6H8O7) oziroma bolj natančno z enim od njenih anionov (po dve kobaltovi(II), nikljevi(II) in bakrovi(II)): (C(NH2)3)8[Co4L4]·8H2O 1, Na2[Co2(HL)2(H2O)4]·6H2O 2, (C(NH2)3)8[Ni4L4]·8H2O 3, Na2[Ni2(HL)2(H2O)4]·6H2O 4, [Cu2L(H2O)]n 5, in bakrovi(II) spojini 6, kateri nismo uspeli določiti formule. Sinteze so bile izvedene s preprostimi kovinskimi izhodnimi spojinami, natrijevim citratom(3-) in vse v vodi. Spojine 1, 2, 3 in 5 so bile že opisane v literaturi, kar smo potrdili z rentgensko difrakcijsko analizo. S tako analizo smo tudi potrdili izostrukturnost spojin 1 in 2 s spojinama 3 in 4. Za spojini 4 in 5 se rezultati CHN elementne analize dobro ujemajo z izračunanimi vrednostmi predlaganih formul spojin. Posledično lahko sklepamo, da so bili sintezni produkti spojin 4 in 5 čiste snovi. Rezultati spojin 1 in 3 se ujemajo slabše, kar kaže na prisotnost nečistoč. Takšna elementna analiza za 2 in 6 ni omogočala neke povezave z določeno formulo. Z infrardečo spektroskopijo smo potrdili vezavo citratnih anionov v naše koordinacijske spojine in vezavo gvanidinskega kationa v spojine 1, 3 in 6. Izrazita podobnost IR spektrov je opazna za izostrukturna para spojin 1 in 3 z gvanidinijevim kationom ter 2 in 4 brez tega kationa. Spektra bakrovih spojin 5 in 6 se delno ujemata: 6 z gvanidinijevima spojinam in 5 z ostalima dvema. Razlike, opazne pri UV-Vis spektrih oziroma pri barvah spojin, kažejo na prisotnost različnega centralnega kovinskega(II) iona (Co 1/2, Ni 3/4 in Cu 5/6). Za spojine 1, 2 in 4 se izmerjeni efektivni magnetni moment dobro ujema s pričakovanimi vrednostimi za spojine z ustreznim kovinskim ionom. Meritve za spojine 3, 5 in 6 pa se le delno ujemajo s pričakovanimi vrednostimi. Znižana vrednost za te spojine je lahko posledica antiferomagnetne interakcije ali vprašljive čistosti vzorca.

Keywords

koordinacijske spojine;kobalt;nikelj;baker;ligandi;citronska kislina;citrat;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [K. Cotman]
UDC: 546.3:547.477(043.2)
COBISS: 87719171 Link will open in a new window
Views: 475
Downloads: 26
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Other data

Secondary language: English
Secondary title: Synthesis and characterization of copper, nickel and cobalt compounds with citric acid anions
Secondary abstract: Six coordination compounds with citric acid (H4L = C6H8O7) or more preciselly with one of its anions were synthesized (two per cobalt(II), nickel(II) and copper(II)): (C(NH2)3)8[Co4L4]·8H2O 1, Na2[Co2(HL)2(H2O)4]·6H2O 2, (C(NH2)3)8[Ni4L4]·8H2O 3, Na2[Ni2(HL)2(H2O)4]·6H2O 4, [Cu2L(H2O)]n 5 and a copper compound with an undetermined formula. Syntheses were performed with simple metal starting compounds, sodium citrate(3-) and all in water. Compounds 1, 2, 3 and 5 were already described in the literature, which we confirmed with X-ray diffraction analysis. Compounds 1 and 2 are isostructural to 3 and 4, respectively. The results of CHN elemental analysis for the compounds 4 and 5 are in agreement with the calculated values of proposed compound formulaes. It can therefore be concluded, that compounds 4 and 5 are pure substances. This type of data for compounds 1 and 3 does not show such agreement, therefore indicating the presence of impurities. For compounds 2 and 6 elemental analysis did not allow correlation with a formula. The CHN elemental analysis results of the compound Citrate anions bonding into all our investigated coordination compounds, as well as guanidine cations bonding into compounds 1, 3 and 6, were confirmed with infrared spectroscopy. IR spectra of isostructural pairs 1 and 3 with guanidinium cation and 2 and 4 without this cation are very similar. IR spectra of 5 amd 6 match partialy: 6 with the guanidinium pair and 5 with the other pair. The UV-Vis spectras well as the color of the six compounds differ due to different central metal cation present (Co 1/2, Ni 3/4 in Cu 5/6). The measured effective magnetic moment of compounds 1, 2 and 4 matches well with expected values for their corresponding metal cations. For compounds 3, 5 and 6 the measurements only match partially with their expected values. The low value of effective magnetic moment for these compounds can be explained with the antiferromagnetic effect or questionable purity.
Secondary keywords: coordination compounds;nickel;copper;cobalt;citrate;
Type (COBISS): Master's thesis/paper
Study programme: 1000375
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Pages: 64 str.
ID: 13668040