Temperature Dependence of the Oxidative Addition of Triethylsilane to Photochemically Generated (η5-C5Cl5)Mn(CO)2

Kent M. Young; Mark S. Wrighton

doi:10.1021/om00106a030

Temperature Dependence of the Oxidative Addition of Triethylsilane to Photochemically Generated (η⁵-C₅Cl₅)Mn(CO)₂

Kent M. Young
, Mark S. Wrighton

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

Near-UV irradiation of (η⁵-C₅Cl₅Mn(CO)₃ in alkane glasses leads to the loss of CO to form a 16e dicarbonyl species. If the photolysis is effected in alkane solution containing Et₃SiH or in neat Et₃SiH, the dicarbonyl thermally reacts with the silane generating (η⁵-C₅Cl₅)Mn(CO)₂H(SiEt3). The rate of the reaction is first order in (η⁵-C₅Cl₅)Mn(CO)₂ and depends on temperature. The ΔH^‡ is 36 ± 4 kJ mol^-1 and the ΔS^‡ is -140 ± 15 J mol^-1 K^-1 from rate measurements in the range 190–240 K. The significant finding is that the value of ΔH^‡ is about the same as that found for the reaction of Et₃SiH with photogenerated (η⁵-C₅H₅)Mn(CO)₂ and (η⁵-C₅Me₅)Mn(CO)₂. Thus, for the series (η⁵-C5R₅)Mn(CO)₂(R = Cl, H, Me) variation in ΔS^‡, not ΔH^‡, is the source of the variation in the reaction rate with Et₃SiH. For R = Cl the reaction rate constant at a given temperature is extrapolated to be 10⁷ times smaller than the reaction rate constant for R = Me.

Original language	English
Pages (from-to)	1063-1066
Number of pages	4
Journal	Organometallics
Volume	8
Issue number	4
DOIs	https://doi.org/10.1021/om00106a030
State	Published - Apr 1989

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@article{47cf4fe7b4a849f09cda20b3d72ffa01,

title = "Temperature Dependence of the Oxidative Addition of Triethylsilane to Photochemically Generated (η5-C5Cl5)Mn(CO)2",

abstract = "Near-UV irradiation of (η5-C5Cl5Mn(CO)3 in alkane glasses leads to the loss of CO to form a 16e dicarbonyl species. If the photolysis is effected in alkane solution containing Et3SiH or in neat Et3SiH, the dicarbonyl thermally reacts with the silane generating (η5-C5Cl5)Mn(CO)2H(SiEt3). The rate of the reaction is first order in (η5-C5Cl5)Mn(CO)2 and depends on temperature. The ΔH‡ is 36 ± 4 kJ mol-1 and the ΔS‡ is -140 ± 15 J mol-1 K-1 from rate measurements in the range 190–240 K. The significant finding is that the value of ΔH‡ is about the same as that found for the reaction of Et3SiH with photogenerated (η5-C5H5)Mn(CO)2 and (η5-C5Me5)Mn(CO)2. Thus, for the series (η5-C5R5)Mn(CO)2(R = Cl, H, Me) variation in ΔS‡, not ΔH‡, is the source of the variation in the reaction rate with Et3SiH. For R = Cl the reaction rate constant at a given temperature is extrapolated to be 107 times smaller than the reaction rate constant for R = Me.",

author = "Young, \{Kent M.\} and Wrighton, \{Mark S.\}",

year = "1989",

month = apr,

doi = "10.1021/om00106a030",

language = "English",

volume = "8",

pages = "1063--1066",

journal = "Organometallics",

issn = "0276-7333",

number = "4",

}

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T1 - Temperature Dependence of the Oxidative Addition of Triethylsilane to Photochemically Generated (η5-C5Cl5)Mn(CO)2

AU - Young, Kent M.

AU - Wrighton, Mark S.

PY - 1989/4

Y1 - 1989/4

N2 - Near-UV irradiation of (η5-C5Cl5Mn(CO)3 in alkane glasses leads to the loss of CO to form a 16e dicarbonyl species. If the photolysis is effected in alkane solution containing Et3SiH or in neat Et3SiH, the dicarbonyl thermally reacts with the silane generating (η5-C5Cl5)Mn(CO)2H(SiEt3). The rate of the reaction is first order in (η5-C5Cl5)Mn(CO)2 and depends on temperature. The ΔH‡ is 36 ± 4 kJ mol-1 and the ΔS‡ is -140 ± 15 J mol-1 K-1 from rate measurements in the range 190–240 K. The significant finding is that the value of ΔH‡ is about the same as that found for the reaction of Et3SiH with photogenerated (η5-C5H5)Mn(CO)2 and (η5-C5Me5)Mn(CO)2. Thus, for the series (η5-C5R5)Mn(CO)2(R = Cl, H, Me) variation in ΔS‡, not ΔH‡, is the source of the variation in the reaction rate with Et3SiH. For R = Cl the reaction rate constant at a given temperature is extrapolated to be 107 times smaller than the reaction rate constant for R = Me.

AB - Near-UV irradiation of (η5-C5Cl5Mn(CO)3 in alkane glasses leads to the loss of CO to form a 16e dicarbonyl species. If the photolysis is effected in alkane solution containing Et3SiH or in neat Et3SiH, the dicarbonyl thermally reacts with the silane generating (η5-C5Cl5)Mn(CO)2H(SiEt3). The rate of the reaction is first order in (η5-C5Cl5)Mn(CO)2 and depends on temperature. The ΔH‡ is 36 ± 4 kJ mol-1 and the ΔS‡ is -140 ± 15 J mol-1 K-1 from rate measurements in the range 190–240 K. The significant finding is that the value of ΔH‡ is about the same as that found for the reaction of Et3SiH with photogenerated (η5-C5H5)Mn(CO)2 and (η5-C5Me5)Mn(CO)2. Thus, for the series (η5-C5R5)Mn(CO)2(R = Cl, H, Me) variation in ΔS‡, not ΔH‡, is the source of the variation in the reaction rate with Et3SiH. For R = Cl the reaction rate constant at a given temperature is extrapolated to be 107 times smaller than the reaction rate constant for R = Me.

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U2 - 10.1021/om00106a030

DO - 10.1021/om00106a030

M3 - Article

AN - SCOPUS:0011465424

SN - 0276-7333

VL - 8

SP - 1063

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JO - Organometallics

JF - Organometallics

IS - 4

ER -

Temperature Dependence of the Oxidative Addition of Triethylsilane to Photochemically Generated (η⁵-C₅Cl₅)Mn(CO)₂

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