DITIN(IV) CHALCOGENIDE ANIONS - SE-77, SN-119, AND TE-125 SOLUTION NMR-STUDY OF THE SN(2)CH(6)(4-) AND SN(2)CH(7)(4-) (CH=SE, TE) ANIONS, X-RAY CRYSTAL-STRUCTURES AND RAMAN-SPECTRA OF K-, (ENH(+))(2)(2,2,2-CRYPT-K+)(2)SN2SE64-, AND (K+)(2)(2,2,2-CRYPT-K+)(2)SN2TE64-, AND X-RAY CRYSTAL-STRUCTURES OF K+(2,2,2-CRYPT-K+)(2)HOSNTE33- AND 2)HOSNTE33-CENTER-DOT-EN((N(CH3)(4)(+))(3)SN2SE64)

The seleno- and tellurostannate(IV) anions Sn(2)Ch(6)(4-) and Sn(2)Ch( 7)(4-) (Ch = Se, Te) have been obtained by extraction of the ternary a lloys KSn0.67Se1.93 and KSn0.63Te1.70 in ethylenediamine (en) and/or l iquid NH3 in the absence and in the presence of nonstoichiometric amou nts of 2,2,2-crypt 21,24-hexaoxa-1,10-diazabicyclo[8.8.8]-hexacosane) with respect to K+. The anions were characterized in solution for the first time by natural abundance Se-77, Sn-119, and Te-125 NMR spectros copy. The magnitudes of the relativistically corrected reduced couplin g constants K-1(Sn-Ch(t))(RC), K-1(Sn-Ch(mb))(RC), and K-1(Sn-Ch(db))( RC) were shown to be consistent with a significant degree of s-charact er in the bonding. The Sn-Ch(mb) and Sn-Ch(t) bond distances observed for the dimeric SnCh(3)(2-) anions, namely Sn(2)Ch(6)(4-), in K+(N(CH3 )(4)(+))(3)Sn2Se64- (1), (enH(+))(2)(2,2,2-crypt-K+)(2)Sn2Se64- (2), a nd (K+)(2)(2,2,2- crypt-K+)(2)Sn2Te64- (3) were shown to correlate wit h the K-1(Sn-Ch)(RC) values, indicating that the solid-state molecular structures of the anions are retained in solution. The Raman spectra of compounds 1-3 are also reported along with their respective factor- group analyses. The novel HOSnTe33- anion, the hydroxide derivative of the SnTe32- anion, has been structurally characterized by X-ray cryst allography in K+(2,2,2-crypt-K+)(2)HOSnTe33- (4) and in K+(2,2,2-crypt -K+)(2)HOSnTe33-. en (5) and represents the first example of a simple mixed hydroxychalcogenide anion of tin.