Iodine Substituted Tetrathiafulvalene Radical Cation Salts with [M(isoq)2(NCS)4]- Anions where M = CrIII, GaIII: Role of I···S and

详细信息    查看全文

• 作者：Katel Hervé ; Olivier Cador ; Sté ; phane Golhen ; Karine Costuas ; Jean-Franç ; ois Halet ; Takashi Shirahata ; Tsuyoshi Muto ; Tatsuro Imakubo ; Akira Miyazaki ; and Lahcè ; ne Ouahab
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：February 7, 2006
• 年：2006
• 卷：18
• 期：3
• 页码：790 - 797
• 全文大小：518K
• 年卷期：v.18,no.3(February 7, 2006)
• ISSN：1520-5002

文摘

The preparation, crystal structures, extended Hückel theory band structure, and density functional theory(DFT) calculations and conducting and magnetic properties of seven new charge-transfer salts, formulatedas (D)₂[M^III(isoq)₂(NCS)₄], where D = DIET (diiodo(ethylenedithio)tetrathiafulvalene), DIETS (diiodo(ethylenedithio)diselenadithiafulvalene), M = Cr, Ga, and isoq = isoquinoline, are reported. For eachdonor two different phases called a and b were obtained. Crystal data for (DIET)₂[Cr(isoq)₂(NCS)₄] (1)are as follows: phase a, triclinic P, a = 9.8645(6) Å, b = 10.3255(8) Å, c = 13.7712(8) Å, =87.905(5), = 75.981(5), = 80.712(2); phase b, triclinic P, a = 10.6760(5) Å, b = 11.3000(6) Å,c = 11.3930(9) Å, = 101.256(2), = 96.755(2), = 97.342(5). All compounds exhibitsemiconductive behavior with room-temperature resistivity ranging from 2 × 10³ to 5 × 10⁴ cm.Donors in the mixed-valence-state form dimers. They are connected to anions through very short I···Scontacts (S2···I2 = 3.248(2) Å for 1a). The magnetic measurements and spin density DFT calculationsrevealed that iodine atoms are good structural agents but are poor magnetic mediators to promotesuperexchange interactions between the donors and the inorganic anions. Our analyses reveal also thatin these charge-transfer salts the magnetic interactions between spin carriers are mainly ensured by shortintermolecular S···S contacts.