TcO 3-core complexes

I he vibrational spectra of the telrabutylammonium salts of [TcOCU], [TcOBry] , and [ rcOU] indicate Qv symmetry for the complex ions (Table 12.4.A). 

Force constants and mean amplitudes of vibration were evaluated. The Tc=0 bond proved to be by far the strongest, exhibiting force constants of more than 8 mdyne/A [92]. 

CsjITcOCIsI Raman IK CszlTcOBr,) Raman IR Tentative assignment 

When a suspension of Tc02-hydrale in water is reacted with a hot aqueous solution of KCN, a honey-colored solution is obtained. After addition of methanol, greenish yellow crystals of K2[TcO(CN)s] -4H20 were isolated which hydrolyzed in aqueous solution slowly in the absence of cyanide ions to form K3[Tc02(CN)4]. Reaction of [TcOCUJ with CN ions in methanol produced / rt/ .v-oxomethoxy-tetracyanotechne-tate(V). [TcO(OMe)(CN)4] . Its [n-(C4Hg)4N] salt formed lilac needles. The Tc=0 stretch of the methoxidc complex appeared at 932 cm , while that of [TcO(CN)5] occured at 910 cm [99]. 

Oxotetracyanoaquotechnetalc(V), [TcO(OH2)(CN)4], was obtained in acid solution by protonation of [Tc02(CN)4] and precipitated with [(CH3)4N] to form blue crystals of [(CH3)4N] TcO(OH2)(CN)4]-2H20. The compound crystallizes in the orthorhombic space group Pmmn with a=12.ll, 6=9.04, c=7.10 A, and Z=2, and is iso-structural with the analogous complex salt of Rc(V). In [TcO(OIl2)(CN)4] the aquo ligand is displaced upon reaction with excess thiocyanate. 

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