Preparation of co-crystals of cadmium(II) coordination polymers: Impact of steric and electronic effects on formation and sustainability of their structures

U okviru ovog diplomskog rada provedena je kokristalizacija koordinacijskih polimera kadmijevih(II) halogenida i halogenpirazina s nekoliko koformera (1,4-dicijanobenzenom, 1,4-benzokinonom, 1,3- dinitrobenzenom). Osim mljevenja potpomognutog kapljevinom (LAG), pojedini kokristali uspješno su priređeni i otopinskom sintezom. Nastali produkti karakterizirani su infracrvenom spektroskopijom (IR), termičkim metodama (TG/DSC) i metodom difrakcije rendgenskih zraka u polikristalnom uzorku (PXRD) kojom je potvrđen nastanak/izostanak kokristala. Iz podataka prikupljenih metodom difrakcije rendgenskih zraka u monokristalnom uzorku (SCXRD) određene su molekulske i kristalne strukture, a ostvarene međumolekulske interakcije u kristalnoj strukturi kokristala uspoređene su s odgovarajućima u koordinacijskom polimeru. Na temelju izračunatih vrijednosti molekulskih elektrostatskih potencijala koformera proučeni su elektronski efekti ključni za održivost kokristala u čvrstom stanju/otopini. Ispitan je i kvantificiran mehanički odziv priređenih kokristala uslijed primjene mehaničke sile na igličaste kristale. Stupanj savitljivosti kokristala [CdI2(I-pz)2][1,4-DCB] uspoređen je sa stupnjem savitljivosti [CdI2(I-pz)2]n iz čega je ustanovljeno da se ugađanjem kristalne strukture (kokristalizacijom) može modificirati (u ovom slučaju povećati) stupanj fleksibilnog odzivaWithin the framework of this thesis, co-crystallization of the halide coordination polymers of cadmium(II) and halopyrazines with several co-formers (1,4-dicianobenzene, 1,4-benzoquinone, 1,3- dinitrobenzene) was carried out. In addition to liquid-assisted milling (LAG), some co-crystals were also successfully prepared by solution synthesis. The resulting products were characterized by infrared spectroscopy (IR), thermal methods (TG/DCS) and an X-ray diffraction method in a polycrystalline sample (PXRD) confirming the formation or absence of co-crystals. Molecular and crystalline structures were determined from the data collected by the single-crystal X-ray diffraction method (SCXRD), and intemolecular interactions in the crystal structure of co-crystals and starting coordination polymers were compared. From the calculated molecular electrostratic potential surfaces values of co-formers, electronic effects crucial for the viability of co-crystals in the solid-state/solution were studied. The mechanical response of crystals of prepared compounds due to the application of mechanical force was investigated and quantified. The bending strain of [CdI2(I-pz)2][1,4-DCB] cocrystal was compared with the bending strain of [CdI2(I-pz)2]n. It has been established that the degree of flexible response can be modified (in this case increased) by tuning the crystal structure (by cocrystallization)