Preparation and Structures of the 2.2.2-Cryptand(1+) Salts of the [Sb2Se4]2-, [As2S4]2-, [As10S3

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• 作者：Donna M. Smith ; Chang-Woo Park ; and James A. Ibers
• 刊名：Inorganic Chemistry
• 出版年：1996
• 出版时间：November 6, 1996
• 年：1996
• 卷：35
• 期：23
• 页码：6682 - 6687
• 全文大小：161K
• 年卷期：v.35,no.23(November 6, 1996)
• ISSN：1520-510X

文摘

2.2.2-Cryptand(1+) salts of the[Sb₂Se₄]^2-,[As₂S₄]^2-,[As₁₀S₃]^2-, and[As₄Se₆]^2-anions have been synthesizedfrom the reduction of binary chalcogenide compounds by K inNH₃(l) in the presence of thealkali-metal-encapsulating ligand 2.2.2-cryptand(4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane),followed byrecrystallization from CH₃CN. The[Sb₂Se₄]^2-anion, which has crystallographically imposed symmetry 2,consistsof two discrete edge-sharing SbSe₃ pyramids with terminalSe atoms cis to each other. The Sb-Se_t bonddistanceis 2.443(1) Å, whereas the Sb-Se_b distance is2.615(1) Å (t = terminal; b = bridge). TheSe_b-Sb-Se_t anglesrange from 104.78(4) to 105.18(5), whereas theSe_b-Sb-Se_b angles are 88.09(4) and88.99(4). The ⁷⁷Se NMRdata for this anion in solution are consistent with its X-ray structure(hars/delta.gif" BORDER=0 > 337 and 124 ppm, 1:1 intensity, -30 C,CH₃CN/CD₃CN). Similar to this[Sb₂Se₄]^2-anion, the[As₂S₄]^2- anionconsists of two discrete edge-sharingAsS₃ pyramidal units. The As-S_t bonddistances are 2.136(7) and 2.120(7) Å, whereas theAs-S_b distancesrange from 2.306(7) to 2.325(7) Å. TheS_b-As-S_t angles range from 106.2(3) to108.2(3), and theS_b-As-S_bangles are 88.3(2) and 88.9(2). The[As₁₀S₃]^2- anionhas an 11-atom As₁₀S center composed of sixfive-memberededge-sharing rings. One of the three waist positions is occupiedby a S atom, and the other two waist positionsfeature As atoms with exocyclic S atoms attached, making each As atomin the structure three-coordinate. TheAs-As bond distances range from 2.388(3) to 2.474(3) Å.The As-S_t bond distances are 2.181(5) and2.175(4)Å, and the As-S_b bond distance is 2.284(6) Å. The[As₄Se₆]^2-anion features two AsSe₃ units joined bySe-Sebonds with the two exocyclic Se atoms trans to each other. Theaverage As-Se_t bond distance is 2.273(2)Å,whereas the As-Se_b bond distances range from2.357(3) to 2.462(2) Å. TheSe_b-As-Se_t angles range from101.52(8) to 105.95(9), and theSe_b-As-Se_b angles range from 91.82(7) to102.97(9). The ⁷⁷Se NMR data forthis anion in solution are consistent with its X-ray structure (hars/delta.gif" BORDER=0 > 564and 317 ppm, 3:1 intensity, 25 C, DMF/CD₃CN).