I have synthesized Co(III)-Hydrazone complex and I want single crystals for SC-XRD measurement. I have tried varied crystal growth techniques: Vapour/solvent diffusion, slow evaporation, and solvent layering , using various solvents(Co(III)complex-soluble and Insoluble) and their ratios as well. Yet, Vapour diffusion of DMF solution of complex with Et2O yielded only micro-crystals(poor for XRD measurement).
Can you please help me with the best crystal growth method to try here. And if possible what solvent/ solvent mixtures should be applied?
Dear Daniel,
you gave already the answer: try as many techniques as you can. You know theost important ones.
I might only add one method: if you have the opportunity to use an autoclave and a heating programme, try to crystallise (or even synthesise) your complex in the autoclave from a volatile solvent as methanol or ethanol avoiding the rather non-volatile DMF or DMSO.
At the same time, there is nothing I can seriously recommend for a complex that I do not have in hand. And definitely, I cannot tell "the best crystal growth method", sorry.
the best technique is slow evaporation at room temperature but it takes very broad time... you can also use the solvothermal technique if your precursors are not soluble in water ...
First you will conduct solubliity characterization of the metal complexes. Most often they will be soluble in DMSO, DMF and probably chloroform. For those that are slightly soluble in ethanol or methanol, you can dissolve in hot solution of 1:1 DMF/methanol, filter and allow to crystallize for few days. If the complexes are soluble in dichloromethane (not very common) but insoluble in ether, you can diffuse ether into dichloromethane solution of the metal complexes. We have obtained good results by using this method for metal complexes of thiourea derivatives.
Dear Daniel KWABENA BOATENG Acheampong, I fully agree with Axel Klein in that it is difficult to suggest the best single crystal growth technique if you don't know the exact nature of the individual compound. However, that attached (rather old) paper might give you some hint. The authors report cobalt(III) hydrazone complexes which were crystallized from benzene. I would try toluene instead of toxic benzene. If your compound is soluble in hot (boiling) toluene, chances are that upon slow cooling to room temperature you will obtain nice crystals.
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