IRON TRICARBONYL COMPLEXES OF CYCLOHEPTATRIENE, CYCLOHEPTADIENE AND CYCLOHEPTADIENIUM ION¹

Olefin and Acetylene Complexes of Transition Metals.

“…The two liquid products can be separated either by liquid phase chromatography (34), or by repeated fractional crystallization at low temperatures (73). It may be noted that although the proton resonance spectra described by the two independent groups (34,73) for the two liquid products are in reasonable agreement, and support the respective formulations, there is some discrepancy in the quoted melting points, particularly in the cycloheptatriene complex (Table II). The cycloheptatriene complex is less stable to aerial decomposition than the cycloheptadiene complex.…”

“…Since cycloheptatriene contains potentially sixelectrons available for donation to transition metals, reaction with iron carbonyls might be expected to give a diamagnetic dicarbonyl C7H8Fe(CO)2, and an orange liquid of this composition was in fact described in a preliminary paper (32). Further investigation (34,73) has shown that the thermal reaction of iron pentacarbonyl with cycloheptatriene gives a mixture of three organometallic complexes, the relative amounts of which vary with reaction conditions; none is the expected dicarbonyl. The complexes are: (a) cycloheptatriene iron tricarbonyl, C7H8Fe(CO)3, an orange-yellow diamagnetic liquid; (b) cyclohepta-1,3-diene iron tricarbonyl, C7Hi0Fe(CO)3, an orange-yellow diamagnetic liquid; (c) bis-(cycloheptatriene)-tri-iron nonacarbonyl (C7H8)2Fe3(CO)g, a yellow crystalline diamagnetic solid.…”

“…If the reaction mixture of Fe(CO)3 and cycloheptatriene is held at 110°for seven days (34), or at 135°for one day (73), cycloheptatriene iron tricarbonyl is the main product; at 135°for five days, however, the cycloheptadiene complex predominates over the cycloheptatriene complex (34,73), and a small yield of the trinuclear complex is obtained. The two liquid products can be separated either by liquid phase chromatography (34), or by repeated fractional crystallization at low temperatures (73).…”

“…If the reaction mixture of Fe(CO)3 and cycloheptatriene is held at 110°for seven days (34), or at 135°for one day (73), cycloheptatriene iron tricarbonyl is the main product; at 135°for five days, however, the cycloheptadiene complex predominates over the cycloheptatriene complex (34,73), and a small yield of the trinuclear complex is obtained. The two liquid products can be separated either by liquid phase chromatography (34), or by repeated fractional crystallization at low temperatures (73). It may be noted that although the proton resonance spectra described by the two independent groups (34,73) for the two liquid products are in reasonable agreement, and support the respective formulations, there is some discrepancy in the quoted melting points, particularly in the cycloheptatriene complex (Table II).…”

The Structure and Synthesis of Firefly Luciferin

“…[2][3][4][5][6][7][8][9][10] (1) This work was supported in part by a grant from the National Science Foundation. [2][3][4][5][6][7][8][9][10] (1) This work was supported in part by a grant from the National Science Foundation.…”