Eastern Illinois University The Keep Masters Theses Student Theses & Publications 1986 Synthesis of Phosphine Trans-Substituted Derivatives of Iron Pentacarbonyl Karl Heinz Hecker Eastern Illinois University This research is a product of the graduate program in Chemistry at Eastern Illinois University. Find out more about the program. Recommended Citation Hecker, Karl Heinz, "Synthesis of Phosphine Trans-Substituted Derivatives of Iron Pentacarbonyl" (1986). Masters Theses. 2642. https://thekeep.eiu.edu/theses/2642 This is brought to you for free and open access by the Student Theses & Publications at The Keep. It has been accepted for inclusion in Masters Theses by an authorized administrator of The Keep. For more information, please contact [email protected]. THESIS REPRODUCTION CERTIFICATE TO: Graduate Degree Candidates who have written formal theses. SUBJECT: Permission to reproduce theses. 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Please sign one of the following statements: Booth Library of Eastern Illinois University has my permission to lend my thesis to a reputable college or university for the purpose of copying it for inclusion in that institution's library or research noldings. /2- /$ - l'f 5'1 Date Author I respectfully request Booth Library of Eastern Illinois University not allow my thesis be reproduced because � Date Author m SYNTHESISOF PHOSPHINEDERIVATIVES TRANS-SUBSTITUTED OF IRON PENIACARBONYL (TITL.E) BY Karl Heinz Hecker THESIS SUBMITIED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science IN GRADUATE SCHOOL, EASTERN ILLINOIS UNIVERSITY THE CHARLESTON, ILLINOIS 1986 YEAR I HEREBY RECOMMEND THIS THESIS BE ACCEPTED AS FULFILLING THIS PART OF THE GRADUATE DEGREE CITED ABOVE DEPARTMENT HEAD SY NTHESIS OF PHOSPHINE TRANS-SUBSTITUTED DERIVAT IVES OF IRON PE NTACARB ONYL 1;>-1i-g� Date /2-/tf·?' Dr . D. w. Ebdon Date J '). -) �-$??,, Dr . G. L. Hende rson Date Dr. E. A. Keiter To those closest to me - Mama , Jo sef, Ursula, Jut ta , Michael, and Wanping . 1 ACKNOWLEDGEMENT I wish to express my sincere appreciation to Dr. Richard L. Keiter for suggesting the problem and for pro­ viding needed guidance, help, and understanding throughout the investigation . I want to thank Dr. J. w. Ellis for allowing me to work in his lab and use his equipment . I extend my appreciation to Dr . D. w. Ebdon, Dr. G. L. Henderson , and Dr. E. A. Keiter for their contribution of time and talent as members of my thesis commitee and for their help provided otherwise . I thank Carol Boecker for preparing some of the iron 1 carbonyl complexes and for performing the H NMR experi- ment . 11 ABSTRACT TITLE OF THESIS: Synthesis of phosphine trans-substituted derivatives of iron pentacarbonyl NAME : Karl Heinz Hecker THESIS DIRECTED BY : Dr . Richard L. Keiter The synthesis of trans-Fe CC0> CPR > CPR = , 3 3 2 3 PPh3 PPh Me , PPh CBCH , PCc-c a > , PCn-c a > , PPh H> can be 2 2 2 6 11 3 4 9 3 2 achieved by refluxing iron pentacarbonyl under reducing conditions in the presence of ligand in 1-butanol . Addi­ tion of iron pentacarbonyl to a 1-butanol solution of sodium borohydride at room tempe rature results in a quantitative conversion of the iron carbonyl complex to the corresponding mononuclear formyl complex . Upon heating the initially formed formyl spec ies decomposes to form the tetracarbonylhydridoferrate (O) anion. This hydride is be­ lieved to undergo reaction with the phosphine ligand to yield the isolated trans-substituted iron complex . Fe (CHO) Fe (CO> s CC0> 4 RT , 1-butanol - BH3 heat CC0> Fe CCH0) HFe (CO) 4 • 4 - co 2 PR - 3 HFe(C0> _ Fe (CO) CPR ) 4 ___......__ _,.- 3 3 2 - CO, - H 111 Even though traces of monosubstituted product were detected in the crude reaction mixture by infrared spec­ troscopy , uncontaminated trans-substituted complexes were isolated after crystallization from dichloromethane/metha­ nol . All complexes have been found to be sensitive to oxy9en if in solution, with the rate of decomposition depending on the kind of ligand . However, if they are dry and under vacuum no apparent decomposition takes place . All synthesized complexes have been characterized by IR spec­ troscopy, 31P NMR , and by their melting points . The value of the presented synthesis is based on its high selectivity, extremely short reaction time , good to very good yields , and its simplicity. 1v "PROOF : Evidence having a shade more of plausi­ bility than of unlikelihood ." Amb rose Bierce "REASON: To weigh probabilities in the scales of desire." Ambrose Bierce v TABLE OF CONTENTS Abstract ••••••••••••••••••••••.••••••••••••••••••••••••iii Table of Contents •••••••••••••••••••••••••••••••••••••••vi List of Tables •.•••••••.•••••••••.•••••••••••••••••••••••x List of Figures •••••••••••••••••••••••••••••••••••••••••xi Chapter I - Introduction I.l Phosphine Substituted Derivatives of Iron Pentacarbonyl ••••••••••••••••••••••••••••••••••••••••l CPR Synthesis ••••••••••3 I.2 Previous Methods of Fe <co>3 3 > 2 2.1 Methods Based on CO Dissociation •••••••••••••••••3 2.1.1 Thermal Dissociation of C0 •••••••••••••••••••••••3 2.1.2 Photochemical Dissociation of C0 •••••••••••••••••6 2.1.3 Combination of Photochemical and Thermal Reactions •••••••••••••••••••••.••••••••••••••••••8 2.2 Catalyzed Substitution Reactions of Iron Pentacarbonyl •••••••••••••••••••••••••••••••••••10 2.2.1 Catalysis by Polynuclear Iron Carbonyl Anions •••10 2.2.2 Transition Metal Catalyzed Reactions ••••••••••••12 2.2.3 Hydride Facilitated Reactions •••••••••••••••••••15 v1 I.3 Conclusion ••••.••••••••••••••••.••••••••••••••••••..21 Chapter II - Experimental II.l General Considerations •••••••••••••••••••••••••••••23 II.2 Preparation of Substituted Iron Carbonyl Complexes ••••••••••••••••••••••••••••••••••••••••••24 CPR > •••••••••••24 2.1 Preparation of Fe Cco> 3 3 2 Complexes 2.1.1 Method I •••••••••••••••••••••••••••••••••••••••24 2.1.2 Method II ••••••••••••••••••••••••••••••••••••••25 2.2 Reactions Performed under Modified Conditions ••••26 2.2.1 Reaction of Fe <co> in a 1:1 Ratio •••26 5 with PPh3 + - 2.2.2 Preparation of CPCc N cco> ••••••28 6a5 > 3 > 2 4Fe(CHO) - 1 2.2.3 cco> 4Fe CCHO) -Decomposition( H NMR Experiment ).29 2.2.4 Reaction of Tetracarbonylhydridoferrate(0) •••••30 2.2.s Preparation of Fe Cco> •••••••31 3 CPPh3 > 2 in Ethanol 2.2.6 Investigation of the Gaseous Side Products •••••33 II.3 Attempted Preparations •••••••••••••••••••••••••••••34 3.1 Photochemical Preparation of Fe Cco> .34 3 CPPh2CHCH2> 2 3.2 ••••••••••••••••••37 Preparation of Fe Cco> 3 CAsPPh3 > 2 3�2.1 Preparation by Method I ••••••· ••••••••••••••••••37 3.2.2 Preparation under Modified Conditions ••••••••••37 v11 Chapter III - Results and Discussion III .I Yields and Physical Data ••••••••••••••••••••••••••39 1.1 Summation of Experimental Data ••••••••••••••••••39 1.2 Interpretation of Infrared Spectra ••••••••••••••42 31 1.3 Interpretation of P NMR Spectra •••••••••••••••48 1.4 Miscellaneous •••••••••••••••••••••••••••••••••••54 III.2 Reaction Mechanism ••••••••••••••••••••••••••••••••56 2.1 Formation of Tetracarbonylformylferrate <0> ••••••56 2.2 Thermally Facilitated Hydride Migration •••••••••70 2.3 Reactivity of Tetracarbonylhydridoferrate(0) ••••82 2.4 Proposed Mechanism ••••••••••••••••••••••••••••••94 III.3 Investigation of the Gaseous Side Products •••••••104 3.1 Analysis of the Composition of the Gas •••••••••104 3.1.1 Infrared Analysis of the Gas •••••••••••••••••104 3.1.2 Cooling Experiment •••••••••••••••••••••••••••110 3.2 ••••••• Determination of the Volume of H2 Formed 110 3.3 Investigation of the Origin of the Gas •••••••••112 3.4 Conclusion •••••••••••••••••••••••••••••••••••••119 III .4 Summary and Conclusion ••••••••••••••••••••••••••••120 Addendum •••••••••••••••••••••••••••••••••••••••••••••••122 Bibliography •••••••••••••••••••••••••••••••••••••••••••123 v111 Appendix A: Summary of Repo�ted Preparations of > Fe(C0> 3 CPR3 2 Complexes A-8 Appendix B: Attempted Photochemical Preparation of 2 Fe CC0) 3CPPh2CHCB2> 2 B- Appendix C: Determination of IR Absorptions of Fe(C0> CPR > 3 3 2 C-3 1x LIST OF TABLES Tab. page 1. Yields and Physical Data of Fe(C0> 3 <PR3 > 2 Complexes Part A .••••••••.••••••.•••••••••••••••••••••••••••••40 Part B ••••••••••••••••..•••...••.•••.•...•..••.•.••.•41 2. Rotational Fine Structure of the Vibration-Rotation Band of C0 .••••••••••••••••••••••••••••••••••••••••109 1 • ••• 3. a NMR Data of Butanol and Alkoxyboron Compound . 117 x LIST OF FIGURES Fig . page CPBu ••••45 1. IR Spectrum of Fe Cco> 3 3 > 2 in Dichloromethane 2. IR Spectrum of Fe CC0> CPBu in Chloroform •••••••••46 3 3 > 2 3. IR Spectrum of Fe Cco> <PPh > in Chloroform ••••47 3 2CBCH2 2 31 p NMR Spectrum of Fe Cco> (C oupled) •••••••49 4. 3 <PPh2e> 2 31 5. P NMR Spectrum of Fe <co> •••••51 3 CPPh2e> 2 CDecoupled) 31 6. p NMR Spectrum of Fe CCo> CP Cc a > > •••••••••••52 3 -c6 11 3 2 7. IR Spectrum of the Carbonyl Region of Formyltetra- carbonylferrate CO> Anion ••••••••••••••••••••••••••••59 8. IR Spectrum of the Carbonyl Region of the Formyl Com- plex ....•...........................................60 9. IR Spectrum of PPNCCHO)Fe(C0) ······················62 4 10. Comparison: Formyl Complex in Different Environ- ments (Comparison of IR Spect ra) ••••••••••••••••••••65