Transition-Metal Carbonyl Complexes of 2,5-Diferrocenyl-1-phenyl-1H-phosphole

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• 作者：Dominique Miesel ; Alexander Hildebrandt ; Marcus Korb ; Dieter Schaarschmidt ; Heinrich Lang
• 刊名：Organometallics
• 出版年：2015
• 出版时间：September 14, 2015
• 年：2015
• 卷：34
• 期：17
• 页码：4293-4304
• 全文大小：589K
• ISSN：1520-6041

文摘

Pentacarbonyl(2,5-diferrocenyl-1-phenyl-1H-phosphole)metal complexes 3a鈥?b>c (3a, M = Cr; 3b, M = Mo; 3c, M = W) have successfully been synthesized by the reaction of 2,5-diferrocenyl-1-phenyl-1H-phosphole (1) with M(CO)₅(thf) (2a, M = Cr; 2b, M = Mo; 2c, M = W). Further irradiation of 3a鈥?b>c with 1 equiv of 1 in tetrahydrofuran leads to tetracarbonylbis(2,5-diferrocenyl-1-phenyl-1H-phosphole)metal complexes 4a鈥?b>c (4a, M = Cr; 4b, M = Mo; 4c, M = W). In addition, the reaction of 1 with Fe₂(CO)₉ gave tetracarbonyl(2,5-diferrocenyl-1-phenyl-1H-phosphole)iron (6) and heptacarbonyl[渭-(2,3,4,5-畏)-1-(2,5-diferrocenyl-1-phenyl-1H-phosphole)]diiron (7), respectively. Treatment of 2,5-diferrocenyl-1-phenyl-1H-phosphole sulfide (8) with Fe₂(CO)₉ afforded tricarbonyl[(2,3,4,5-畏)-(2,5-diferrocenyl-1-phenyl-1H-phosphole 1-sulfide)]iron (9). Complexes 3b,c, 4c, 7, and 9 have been characterized by single-crystal X-ray diffraction. Molecules 3b,c and 4c exhibit a distorted-octahedral geometry, whereas in 4c the two phosphole units are cis-oriented. Coordination of the dienic system to Fe(CO)₃ in 7 and 9, respectively, resulted in a deflection of the phosphorus atom from the C₄ plane. Electrochemical measurements of 3a鈥?b>c, 4a鈥?b>c, and 9 demonstrated that the ferrocenyl units can be oxidized separately. The coordination of the dienic system to the Fe(CO)₃ building block leads to a decrease of the redox splitting (螖E掳鈥?= 190 mV) in comparison to 8 (螖E掳鈥?= 240 mV). Mixed-valence [3a鈥?b>c]⁺, [4a鈥?b>c]²⁺, and [9]⁺ show IVCT absorptions of weak to moderate strengths. The coordination of the phosphorus atom to M(CO)₅ in 3a鈥?b>c has no significant influence on the metal鈥搈etal interaction in the mixed-valent species. However, the coordination of the dienic system in 9 results in a significantly decreased electronic communication of the Fc/Fc⁺ termini via the heterocyclic core.