Molybdenum(VI) complexes with a hydrazone derived from 2-hydroxybenzaldehyde and adipic acid dihydrazide

Abstract

U ovom su radu opisani uvjeti priprave bis(2‐hidroksibenziliden)butan‐1,4‐dihidrazona, H4L, kao i odgovarajućih dinuklearnih kompleksnih spojeva molibdena(VI). Reakcijom dioksobis(pentan‐2,4‐ dionato)molibdena(VI) s bis(2‐hidroksibenziliden)butan‐1,4‐dihidrazonom u različitim donorskim otapalima priređeni su spojevi općenite formule [Mo2O4L(D)2], gdje je L deprotonirani oblik heksadentatnog liganda H4L, a D = MeOH, EtOH, CH3CN, DMSO ili DMF. U slučaju spoja [Mo2O4L(EtOH)2] dobivene su tri polimolimorfne forme te solvat [Mo2O4L(EtOH)2]∙2EtOH. Kompleksi su priređeni „klasičnom“ otopinskom sintezom i/ili solvotermalnim postupkom. U svim slučajevima se radi o dinuklearnim kompleksima u kojima se oba atoma molibdena nalaze u oktaedarskom okruženju s labilno vezanim molekulama D. Dodatno je istražena mogućnost selektivnog uklanjanja labilno vezane molekule metanola spoju [Mo2O4L(MeOH)2] zagrijavanjem te mljevenjem. Tim postupcima su pripravljeni spojevi [Mo2O4L] te [Mo2O4L]x. Izlaganjem spoja [Mo2O4L] parama metanola, etanola ili N,N‐dimetilformamida bilo je moguće pripraviti odgovarajuće kompleksne spojeve tipa [Mo2O4L(D)2] ( D = MeOH, EtOH, DMF). Izlaganjem spoja [Mo2O4L]x parama metanola ili etanola bilo je moguće pripraviti spojeve [Mo2O4L(MeOH)2] te [Mo2O4L(EtOH)2]∙2EtOH. Svi spojevi su identificirani i okarakterizirani na temelju podataka infracrvene spektroskopije, difrakcije rendgenskog zračenja na praškastom uzorku, metodama termičke analize te u slučajevima kada je to bilo moguće difrakcijom rendgenskog zračenja na jediničnom kristalu. Spoj H4L kao i [Mo2O4L(EtOH)2] te [Mo2O4L(EtOH)2]∙2EtOH dodatno su okarakterizini u otopini spektroskopijom NMR.Synthesis of bis(2‐hydroxybenzilidene)butane‐1,4‐dihydrazone, H4L, and its corresponding dinuclear molybdenum(VI) are described in this thesis. Reactions of dioxobis(pentane‐2,4‐dionato) molybdenum(VI) with the bis(2‐hydroxybenzilidene)butane‐1,4‐dihydrazone in different solvents yielded complexes of general formula [Mo2O4L(D)2], where L denotes deprotonated form of hexadentate ligand, H4L, while D represents MeOH, EtOH, CH3CN, DMSO or DMF. In the case of [Mo2O4L(EtOH)2] altogether three polymorphic phases were isolated along with its solvate, [Mo2O4L(EtOH)2]∙2EtOH. Complexes were prepred via „classic“ solution procedures and/or by solvothermal route. In all cases complexes are dinuclear, while both molybdenum(VI) atoms are found in octahedral environment and have ancillary ligand D loosely bound. A possibility of selective removal of methanol ligand of the [Mo2O4L(MeOH)2], by heating or by milling, was investigated as well. Such procedures yielded coordinatively unsaturated compounds [Mo2O4L] and [Mo2O4L]x By exposing [Mo2O4L] to methanol, ethanol or N,N‐dimethyformamide vapors it was possible to obtain corresponding complexes of the type [Mo2O4L(D)2] ( D = MeOH, EtOH, DMF). Exposure of [Mo2O4L]x to methanol and ethanol vapors led to [Mo2O4L(MeOH)2] and [Mo2O4L(EtOH)2]∙2EtOH. All isolated compounds were identified and characterized by means of IR spectroscopy, X‐ray powder diffraction, thermal analysis and when applicable single crystal X‐ray diffraction. Compounds H4L as well as [Mo2O4L(EtOH)2] and [Mo2O4L(EtOH)2]∙2EtOH were additionally investigated in solution via NMR spectroscopy. Diploma thesis contain