| Abstract | U okviru ovog rada pripravljena su, reakcijom karbonohidrazida i odgovarajućeg aldehida u množinskom omjeru 1:2, dva disupstituirana simetrična derivata karbonohidrazida, 1,5-bis(2,3-dihidroksibenziliden)karbonohidrazid, H4L3OH-3OH i 1,5-bis(2,4-dihidroksibenziliden)karbonohidrazid, H4L4OH-4OH. Također, pripravljena je i serija monosupstituiranih karbonohidrazida izvedenih iz odgovarajućih piridinkarbaldehida, 1-(piridin-2-ilmetiliden)karbonohidrazid, H2L2py, hidrat 1-(piridin-3-ilmetiliden)karbonohidrazid, H2L3py·1,5(H2O) i 1-(piridin-4-ilmetiliden)karbonohidrazid, H2L4py. Konačno, korištenjem asimetričnih monosupstituiranih derivata kao ishodnih spojeva, u reakcijama s 2,3- dihidroksibenzaldehidom ili 2,4-dihidroksibenzaldehidom pripravljena je serija asimetričnih disupstituiranih karbonohidrazida, 1-(2,3-dihidroksibenziliden)-5-(piridin-2-ilmetiliden)karbonohidrazid, H3L2py-3OH, 1-(2,3-dihidroksibenziliden)-5-(piridin-3-ilmetiliden)karbonohidrazid, H3L3py-3OH, 1-(2,3-dihidroksibenziliden)-5-(piridin-4-ilmetiliden)karbonohidrazid, H3L4py-3OH, 1-(2,4-dihidroksibenziliden)-5-(piridin-2-ilmetiliden) karbonohidrazid, H3L2py-4OH, 1-(2,4-dihidroksibenziliden)-5-(piridin-3-ilmetiliden)karbonohidrazid, H3L3py-4OH i 1-(2,4-dihidroksibenziliden)-5-(piridin-4-ilmetiliden)karbonohidrazid, H3L4py-4OH.
Pripravljeni spojevi okarakterizirani su na temelju podataka infracrvene spektroskopije, difrakcijom rentgenskog zračenja na praškastom uzorku, elementnom analizom, metodama termičke analize te difrakcijom rentgenskog zračenja na jediničnom kristalu.
Većina pripravljenih karbonohidrazida dala je dvije kristalnih forme u čvrstom stanju, uglavnom solvat i odgovarajuću nesolvatiranu formu. Detaljna strukturna analiza priređenih kristalnih formi otkriva kako simetrični disupstituirani karbonohidrazidi u čvrstom stanju poprimaju sin konformaciju, dok se asimetrični nalaze u anti konformaciji. |
| Abstract (english) | Within this work, two disubstituted symmetrical carbohydrazides, 1,5-bis(2,3-dihydroxy-benzylidene)carbohydrazide, H4L3OH-3OH and 1,5-bis(2,4-dihydroxybenzylidene)carbohydrazide, H4L4OH-4OH were prepared by the reaction of carbohydrazide and appropriate aldehyde in the molar ratio 1:2. Moreover, a series of monosubstituted carbohydrazides were derived from carbohydrazide, 1-(pyridine-2-ylmethylidene)carbohydrazide, H2L2py, 1-( pyridine-3-ylmethylidene)carbohydrazide hydrate, H2L3py·1,5(H2O) and 1-( pyridine-4-ylmethylidene)-carbohydrazide, H2L4py. Using asymmetrical monosubstituted carbohydrazides as precursors in reactions with 2,3- or 2,4-dihydroxybenzaldehide, series of asymmetrical disubstituted carbohydrazides were obtained, 1-(2,3-dihydroxy-benzylidene)-5-(pyridine-2-ylmethylidene)carbohydrazide, H3L2py-3OH, 1-(2,3-dihydroxybenzylidene)-5-( pyridine-3-ylmethylidene)carbohydrazide, H3L3py-3OH, 1-(2,3- dihydroxybenzylidene)-5-( pyridine-4-ylmethylidene)carbohydrazide, H3L4py-3OH, 1-(2,4-dihydroxybenzylidene)-5-( pyridine-2-ylmethylidene)carbohydrazide, H3L2py-4OH, 1-(2,4-dihydroxybenzylidene)-5-( pyridine-3-ylmethylidene)carbohydrazide, H3L3py-4OH i 1-(2,4-dihydroxybenzylidene)-5-( pyridine-4-ylmethylidene)carbohydrazide, H3L4py-4OH.
Prepared compounds were identified and characterized by means of infrared spectroscopy, X-ray powder diffraction, elemental analysis, thermal analysis and when it was possible via single-crystal X-ray diffraction.
Majority of prepared carbohydrazides gave two crystal forms in the solid-state, mostly solvate and the corresponding unsolvated form. Detailed structural analysis of the crystal forms unveils that symmetrical disubstituted carbohydrazides assume a sin conformation in the solid-state, whereas the asymmetrical ones are found in the anti conformation. |
