Cyclopentadienyl allyl palladium explained

Cyclopentadienyl allyl palladium is an organopalladium compound with formula (C₅H₅)Pd(C₃H₅). This reddish solid is volatile with an unpleasant odor. It is soluble in common organic solvents. The molecule consists of a Pd centre sandwiched between a Cp and allyl ligands.

Preparation

This complex is produced by the reaction of allylpalladium chloride dimer with sodium cyclopentadienide:^{[1] [2]}

2 C₅H₅Na + (C₃H₅)₂Pd₂Cl₂ → 2 (C₅H₄)Pd(C₃H₅) + 2 NaCl

Structure and reactions

The 18-electron complex adopts a half-sandwich structure with C_s symmetry, i.e., the molecule has a plane of symmetry. The complex can be decomposed readily by reductive elimination.

C₃H₅PdC₃H₅ → Pd(0) + C₅H₅C₃H₅The compound readily reacts with alkyl isocyanides to produce clusters with the approximate formula [Pd(CNR)₂]_n. It reacts with bulky alkyl phosphines to produce two-coordinated palladium(0) complexes:^[3]

CpPd(allyl) + 2 PR₃ → Pd(PR₃)₂ + C₅H₅C₃H₅

The compound has been used to deposit thin film chemical vapor deposition of metallic palladium.^{[4] [5]}

Notes and References

1. Book: Y. Tatsuno, T. Yoshida, S. Otsuka . Inorganic Syntheses . . 1979 . 19 . 220 . 10.1002/9780470132500 . Shriver . Duward F. . 978-0-470-13250-0.
2. R. B. King . Organometallic Chemistry of the Transition Metals. Organometallic Chemistry of the Transition Metals. III. Reactions between Sodium Cyclopentadienide and Certain Complex Transition Metal Halides . . 10.1021/ic50007a026 . 1963 . 2 . 528 . 3.
3. Otsuka, S. . Yoshida, T. . Matsumoto, M. . Nakatsu, K. J. . Cyclohexyneplatinum(0) Complexes Containing Di-t-butylphenylphosphine, t-butyldiphenylphosphine or Trimethylphosphine . 1976 . . 45 . 1 . 135–142 . 10.1071/CH9920135.
4. Y. G Kim . S. Bialy . R.W. Miller . J. T. Spencer . Dowben A. Peter . Datta S. . Selective area deposition of conducting palladium films on polyimide resins . Mater. Res. Soc. Symp. Proc. . 1989 . 158 . 103–7 . 10.1557/PROC-158-103 . 97425013 .
5. K. Rajalingam . T. Strunskus . A. Terfort . R. A. Fischer . C. Wo . Metallization of a thiol-terminated organic surface using chemical vapor deposition . . 2008 . 24 . 15 . 7886–7994 . 18590295 . 10.1021/la8008927.