Molybdenum(VI) coordination polymers and polyoxometalate hybrides

Potaknut raznolikošću struktura i potencijalnom primjenom u različitim područjima, ovaj diplomski rad opisuje sintezu koordinacijskih polimera i poliksometalatnih hibrida. Sinteze su provedene koristeći dioksobis(pentan-2,4-dionato)molibden(VI) i jedan od četiri izo(nikotinhidrazidna) derivata 2,3- ili 2,4-dihidroksibenzaldehida. Dva porozna koordinacijska polimera dobivena su odabirom otapala koje može ostvariti vodikove veze s lancima polimera. Dodatno je ispitana strukturna transformacija jednog od njih koja je potvrdila značaj veličine šupljina u strukturi na produkt transformacije. Nađeni su i uvjeti koji pogoduju nastanku hibridnih polioksometalata, te su pripravljene četiri heksamolibdatne soli i četiri oktamolibdatne soli. Pored različitog stupnja deprotoniranosti liganda u kompleksnim kationima, dobiven je i hibrid s protoniranim hidrazonom kao kationom. Svi produkti okarakterizirani su na temelju IR spektroskopije, a kada su izolirani homogeni produkti ili pak monokristali, napravljene su termogravimetrijske analize i difrakcija rentgenskog zračenja. Otopine liganada i koordinacijskih polimera analizirane su spektroskopijom NMR.Prompted by the diversity of structures and potential application in different areas, this diploma thesis describes synthesis of coordination polymers and polyoxometalate hybrids. Syntheses were carried out using dioxobis(pentane-2,4-dionato)molybdenum(VI) and one of four iso(nicotinoylhydrazide) derivatives of 2,3- or 2,4-dihydroxybenzaldehyde. Two porous coordination polymers were obtained by selecting a solvent that has hydrogen bonding capability with chains of polymers. Additionally, structural transformation of one of them was examined. This confirmed the importance of cavity size within the crystal structure on the final product formation. Conditions that favour the formation of hybrid polyoxometalates were also found and four hexamolybdate and four octamolybdate salts were prepared. In addition to the different degree of deprotonation of the ligand in complex cations, a hybrid with a protonated hydrazone as a cation was obtained. All products were characterized on the basis of IR spectroscopy and, when homogeneous products or single crystals were isolated, thermogravimetric analyses and X-ray diffraction method. Solutions of ligands and coordination polymers were analyzed by NMR spectroscopy