The solid-state isomerization of cis- and trans-(η5-C5H4Me)Mo(CO)2(P(OiPr)3)I

Abstract

This article is dedicated to the memory of John Osborn -who taught his students and colleagues how to live life to the full.

Organometallic chemistry in the melt phase

“…A range of piano stool complexes of the type RCpML 4 (M = Re, Mo, W) have been synthesized in our laboratories and shown to undergo solventless diag to lat isomerization [82][83][84][85][86]. Variation of the Cp ring substituent R, the metal M and the ligands L, have yielded tens of compounds and provided a wide range of variables for systematic studies (Table 3 -34-36).…”

Solid-state isomerisation reactions of (η5-C5H4R)M(CO)2(PR3′)I (M=W, Mo; R=tBu, Me; R′=Ph, OiPr3)

“…The isomerisation reactions for the new complexes were studied and the general trend was for the isomerisation reaction to occur from the trans to the cis Table 3 Crystal data and structure refinement for the cis and trans isomers of (g 5 …”

“…sional effects, (ii) decomposition effects and (iii) the possibility that the reaction follows a more complex mechanism. The activation data are to be compared with the value for the solvent phase reaction ((g 5 -C 5 H 5 )Mo(CO) 2 (PPh 3 )I ¼ 108 kJ mol À1 in o-dichlorobenzene [10]) and for the corresponding solid-state reaction for (C 5 H 4 Me)Mo(CO) 2 [P(O i Pr) 3 ]I (>68 kJ mol À1 ) [5].…”

“…In an earlier study we noted that (g 5 -C 5 H 4 Me)Mo(CO) 2 [P(O i Pr) 3 ]I underwent a bidirectional cis/trans isomerisation reaction in the solid state that favoured the trans isomer (trans:cis ¼ 70/ 30) [5]. Herein we report an extension of this earlier study to the solid-state cis/trans isomerisation reactions of (g 5 -C 5 H 4 Me)M(CO) 2 (PPh 3 )I (M ¼ Mo, W) and (g 5 -C 5 H 4 R)W(CO) 2 [P(O i Pr) 3 ]I (R ¼ Me, t Bu) in order to evaluate the effect of ring substituents, metals and ligands on the solid-state reaction (Fig.…”

Solid-state cis–trans isomerization reaction of (η5-MeC5H4)W(CO)2P(OiPr)3I

“…This value may relate to either the actual isomerisation reaction of reactant molecules or to the movement of a reaction front within the solid state accompanied or followed by the molecular isomerisation reaction (see later). The value is to be compared with data obtained from other related solid state studies [(g 5 -MeC 5 H 4 )Mo(CO) 2 P(O i Pr) 3 I = 68 ± 10 kJ mol À1 [12] and (g 5 -MeC 5 H 4 )W(CO) 2 PPh 3 I > 160 kJ mol À1 [14], with both values being associated with bidirectional reactions.…”