[CONTRIBUTION FROM THE DEPARTMENT OF CHEMISTRY OF THE UYIVERSITTOF ILLINOIS, URBASA, ILLISOIS, ASD DEPARTMENT O F CHEMISTRY OF THE UNIVERSITY O F CALIFORNIA, LOS ANGBLES, CALIF.]
THE
Reactivity of Organic Hydroxy Groups p to the Coordination Site in Cobalt(II1) Complexes BY WILLIAMC. DRINKARD, H. FREDERICK BAUERAND
JOHN
C. BAILAR,JR.
RECEIVED DECEMBER 3, 1959 The ncw compounds bis-N-hydroxyethyldiethylenetriamine2 cobalt(II1) chloride, tri-(thiocyanat0)-di-N-hydroxyethyldiethylenetriaminel cobalt(II1) and trinitro-(di-N-hydroxyethyIdiethylenetriamine)2-cobalt(III)are reported. A new synthesis of tris-( N-hydroxyethylethylenediamine)2-cobalt(111) ion is reported and its properties arc compared to those recorded in the literature. The unusual inertness of the organic &hydroxy groups is discussed.
Keller and Edwards3 have described the prepa- covered only as a glass by evaporation of the water ration of tris-(N-hydroxyethylethy1enediamine)-co- in vacuuni. The last traces of water are removed balt(II1) chloride and have noted that the organic in vacuum over phosphorus(V) oxide. The prodhydroxy groups are quite inert. The work reported uct is deliquescent. here grew out of attempts to use these hydroxy Of the large number of anions tried, only [Crsubstituents as functional groups in polymer ( N H ~ ) z ( S C N ) ~was ] - found to precipitate the formation. The [Co(etolen)3]C13obtained by Kel- [ C o ( e t ~ l e n ) ~ion ] + ~from water solution. The salt ler and Edwards was an orange, crystalline solid, precipitates a s a purple-red powder which is only but that prepared in this study was dark red. slightly soluble in water. Difficulty was encountered in the preparation of The cobalt(II1) complex of N-hqdroxyethyl[Co(et01en)3]*~ion by the direct air oxidation of diethylenetr iamine was prepared by displacement the cobalt(I1)-amine m i x t ~ r e . ~ Repeated at- of ammonia from [ C O ( N H ~ ) ~ ] C The ~ ~ .chloride tempts to prepare the complex by this method re- of this ion is also dark red, deliquescent and very sulted in a cn. 17yoyield of tris-(ethylenediamine)- soluble in water and ethanol. cobalt(II1) ion. No other product could be isoAttempts to make the hydroxy group of [Colated. The [Co(en)s]C13 was identified by ele- ( ~ t o l e n] CI3 ) ~ and [Co(eto1dien)gjCla react with mental analysis and by comparison of its infrared nitric acid, thionyl chloride, benzoyl chloride and spectrum with that of a known sample of the ethyl- acetyl chloride were equally as unsuccessful as enediamine complex. These large yields of the for the compound reported by Keller and Edwards3 [Co(en)3It3 ion were obtained even though the The complexes were dissolved or suspended in the hydroxyethylethylenediamine had been recrystal- reagent in question and refluxed for several hours. lized as the hydrochloride and twice distilled a t The reagent was then evaporated and the solid reduced pressure. Only the middle fraction was residue dried in vacuum and analyzed. Analyses taken in each distillation. Determination of the showed no change in composition. Reaction with equivalent weight of the purified N-hydroxyethyl- diniethyldichlorosilane resulted in reduction of the ethylenediamine indicates the absence of ethylene- cobalt to the plus two state and decompositioii of diamine in it. The absence of ethylenediamine the complex. also was shown by failure to isolate [Co(en),]C13 The lack of a structural change in the ligand 011 when [C0(etolen)~]Cl3was prepared by displace- coordination was shown by recovery and identiment of ammonia from [Co(N&),j]C&. Addition fication of the amine. Cobalt was precipitated of known aniounts of ethylenediamine to the re- from the complexes of N-hydroxyethylethyleneaction mixture in the latter case allowed the ready diamine and N-hydroxyethyldiethylenetriamine by treatment of the aqueous solutions with hyisolation of [C0(en)~]C13. By displacement of ammonia from [Co(NH3)6]Cl3 drogen sulfide. The amines were recovered and by N-hydroxyethylethylenediamine,a dark red a n a l y ~ e das the hydrochlorides. Because it is felt that the complete lack of recompound is produced. The uncatalyzed reaction occurs extremely slowly in aqueous solution activity of [Co(etolenj3]C13and [Co(etoldien)z]Cl3 a t steam-bath temperatures, but addition of acti- is associated with the charge field about the ion, vated carbon to the hot mixture results in a rapid the neutral complexes [Co(dietoldien)(SCN),] and evolution of ammonia. The resulting product is [Co(dietoldien)(N0z)3] were prepared and their very soluble in water and ethanol and can be re- reactivity investigated. Attempts to effect reactions of the organic hydroxy groups in these ( I ) l l o s t of this research was supported by Contract A P 33(616)conipounds with acetyl chloride, benzoyl chloride, 3209 with t h e Materials Laboratory of Wright A i r Development Center, Wright-Patterson Air Forces Base, Ohio. Reproduction of this thionyl chloride, phenyl isocyanate and nitric acid paper in whole or in part is permitted for a n y purpose of the United resulted in decomposition of the complexes. Thus, States Government. T h e paper for t h e most part is based on a portion no conclusions could be drawn concerning the beof a thesis submitted by William C. Drinkard t o t h e Graduate College havior of the organic ligand in the initial comof t h e University of Illinois in partial fulfillment of t h e requirements for t h e degree of Doctor of Philosophy, 1956. pound. (2) T h e following abbreviations for t h e ligands will be used: N. hydroxyethyldiethylenetriamine, HOCHCHzNHCHiCHzNHCHzCIIzNII, = etul
