Two Metal Centers Bridging Two C₆₀ Cages as a Wide Passage for Efficient Interfullerene Electronic Interaction

Abstract

The reaction of Ir4(CO)8(PMe3)4 with excess C60 in refluxing 1,2-dichlorobenzene, followed by treatment by CNR (R = CH2C6H5) at 70 degrees C, affords a fullerene-metal sandwich complex Ir4(CO)3(mu4-CH)(PMe3)2(mu-PMe2)(CNR)(mu-eta2,eta2-C60)(mu4-eta1,eta1,eta2,eta2-C60) (1), which exhibits an interesting structural feature of two metal atoms bridging the two C60 centers as well as the first example of a mu4-eta1,eta1,eta2,eta2-C60 bonding mode. Compound 1 has been characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction study. A cyclic voltammetry study reveals strong electronic communication between the two C60 centers in 1, which is due to the presence of a wide channel of two metal centers between the two C60 cages for efficient electronic interaction.

Unusual Coupling Reaction of C60 and Benzonitrile with Triosmium Carbonyls To Generate Fullerodiketimide Cluster Complexes

“…It is important to note that two benzonitriles have been activated and added to C 60 to generate an unprecedented fullerodiketimide species, while the second C 60 is bound to the Os 3 cluster in a rare μ,η 2 :η 2 feature. 12 Experiments by varying the solvents, temperatures, and reactants were carried out. Typically, treating Os 3 (CO) 12 and C 60 in refluxing benzonitrile/o-dichlorobenzene gave 1 (5%), 2 (13%), and 3 (9%), while only compound 1 was obtained (20− 26%) in refluxing chlorobenzene (133°C) or o-dichlorobenzene (180°C).…”

Three novel bismetallacyclopropa[60]fullerene complexes formed via intermediate monometallacyclopropa[60]fullerene diphosphine ligands

“…1) consists of two C 60 spheres, which are bridged by two metal centers of a ten-membered metallacycle; the metallacycle is composed of two trans-dppet ligands coordinated to Pd/Pd metal centers. Interestingly, 2 is, to our knowledge, the first structurally characterized group 10 (ii) C 60 /Pt 2 (dba) 3 complex 2 is close to that of 16.57 Å in metallacyclopropa[60]fullerene Ir 2 complex, but the non-bonded metal-to-metal distance of 6.83 Å for 2 is much shorter than the corresponding intermetallic distance of 8.104 Å in the Ir 2 complex [13]. The two C-C double bonds C(73)-C(74)@C(73 A)-C(74 A) = 1.290(14) Å for 2 are slightly shorter than the common C-C double bond (1.34 Å ).…”

“…Among such fullerene derivatives bisand multimetallacyclopropa [60]fullerenes are of particular interest; this is largely because new chemical and physical properties might be possibly induced through interactions between C 60 spheres and/or metal centers [2,3]. On the basis of our study on metallacyclopropa[60]fullerenes [4], we have recently synthesized and characterized three novel bismetallacyclopropa [60]fullerenes (g 2 -C 60 )M(l-g 1 ,g 1 -trans-Ph 2 PCH@CH PPh 2 ) 2 M(g 2 -C 60 ) (1, M = Pt; 2, M = Pd) and (g 2 -C 60 ) Pd(l-g 1 ,g 1 -trans-Ph 2 PCH@CHPPh 2 ) 2 Pt(g 2 -C 60 ) (3), in which a ten-membered phosphametallacycle containing Pt/Pt, Pd/Pd, or Pd/Pt metal centers is sandwiched in between two C 60 spheres (Scheme 1).…”

“…The precipitate was washed successively with toluene, hexane and diethyl ether, and finally dried in vacuum to afford the homodinuclear bisfullerene complexes (g 2 -C 60 )Pt(l-g 1 ,g 1 -trans-Ph 2 PCH@CHPPh 2 ) 2 Pt(g 2 -C 60 ) (1) and (g 2 -C 60 )Pd(l-g 1 ,g 1 -trans-Ph 2 PCH@CHPPh 2 ) 2 Pd(g 2 -C 60 ) (2) in 82% and 92% yield. Similarly, the novel heterodinuclear Pd/Pt bisfullerene complex (g 2 -C 60 ) Pd(l-g 1 ,g 1 -trans-Ph 2 PCH@CHPPh 2 ) 2 Pt(g 2 consisting of 36 mg (0.05 mmol) of C 60 , 29 mg (0.05 mmol) of Pd(dba) 2 and 39 mg (0.10 mmol) of trans-dppet in 25 ml of toluene was stirred at room temperature for 1 h and then to the resulting green solution were added 36 mg (0.05 mmol) of C 60 and 28 mg (0.025 mmol) of Pt 2 (dba) 3 . The new mixture was stirred at this temperature for 5 h to give a precipitate.…”

Iridium: Organometallic Chemistry

“…Quite a variety of exohedral iridium fullerene compounds have been characterized including complexes of 96- 98 An example of such a complex was shown earlier in compound (50).…”