テトラチアフルワレン (TTF) 導体における水素結合補助自己ドーピング
Yuka Kobayashi1, Mayu Yoshioka, Kazuhiko Saigo
1Waseda Institute for Advanced Study, Waseda University, Tokyo, 169-8050, Japan. yuka@aoni.waseda.jp
Journal of the American Chemical Society
|July 3, 2009
まとめ
アムニウムテトラチアフルバレン-2-カルボキシラート (TTFCOO(-) NH((4) ((+)) は,プロトネーションにより,断熱器から自己ドーピングの導体へと変化します. 水素結合は,この変換を容易にし,半導体特性を持つ新しい"水素結合補助自己ドーピング導体"を作成します.
科学分野:
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
- オーガニック・エレクトロニクス
背景:
- テトラチアフルバレン (TTF) 誘導体は,その伝導特性のために広範に研究されています.
- 有機導体における制御された自己ドーピングを達成することは,依然として大きな課題です.
- 電子特性を調節する際の分子間相互作用の役割を理解することは極めて重要です.
研究 の 目的:
- アンモニアムテトラチアフルワレン-2-カルボキシラート (TTFCOO(-) NH(4) ((+)) を合成し,特徴づけました.
- この自己ドーピング導体のキャリア生成機構と分子軌道特性を解明する.
- 導電性行為に対する水素結合の影響を調査する.
主な方法:
- TTFCOOHからTTFCOO ((-) NH ((4) ((+)) を合成する.
- UV-vis,ESR,および1H NMRスペクトロスコーピーを用いて特徴づけました.
- 結晶構造を決定するX線結晶学.
- 分子軌道計算 (クラスターモデルと初期周期計算).
- 電流伝導性と同位体効果の測定.
主要な成果:
- 絶縁性TTFCOOHは,導電性シグマ=2.0×10−4 S/cmで300 Kでホールドーピングの導体 (TTFCOO(-) NH(4) ((+)) に変換される.
- TTF部分のプロトネーションにより,根幹種 (TTF(*+) COO(-) NH(4) ((+)) が生成されます.
- X線構造は,水素結合で結びついている超分子TTFCOO(-) 配列を明らかにする.
- 分子軌道の計算は,放射性物質の準閉殻状態を示している.
- 水素結合は,大きな同位体効果によって証明される電子伝導に大きく貢献します.
結論:
- TTFCOO(-)NH(4)(+) は新しい"水素結合補助自己ドーピング導体"である.
- 自己ドーピングは,TTFユニットのプロトネーションによって達成されます.
- 水素結合ネットワークは,TTF分子を組み立て,半導体振る舞いを促進する上で重要な役割を果たします.
- この研究は,調節性特性を有する有機導管を設計するための新しい戦略を提供します.
関連する概念動画
Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Valence Bond Theory
Overview of Valence Bond Theory
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...


