Synthesis and reactivity of a tethered diene cyclopentadiene, (C5Me4H)SiMe2(CH2CHCHCHCH2), and its alkali metal salts

Rare-Earth-Metal/Platinum Heterobinuclear Complexes Containing Reactive Ln-alkyl groups (Ln = Y, Lu): Synthesis, Structural Characterization, and Reactivity

“…Hence, it is plausible that fragmentation of the C 5 Me 4 SiMe 2 CH 2 PPh 2 ligand occurs concurrently with the formation of 3a and 3b to afford 5 as a result of Si−C bond cleavage. The similar Si−C bond cleavage in Cp ligands was also reported previously …”

Alkali-Metal Sandwich Complexes of a 1,2-Diaza-3,5-diborolyl Ligand Featuring η1, η2, η3, and η4 Coordination Modes

“…The distances between potassium and the methyl substituents of the ring carbon are quite short as a result of the unusual position of the potassium ions, on the outside of the columns formed by the CB 2 N 2 rings (Figure and ). The K−C(2) distances range between 3.203(4) and 3.331(3) Å, only 0.05−0.30 Å longer than the K−C(1) bonds and shorter than some of the distances between potassium and the ring carbon in polymeric potassium cyclopentadienyls (2.95 Å to over 3.30 Å). 29b,32c,h,35b, This geometry is not observed in any of the other compounds described in this paper or in other reported potassium sandwich compounds.…”

“…The multidecker sandwich structure in 4a , where potassium ions have a lower coordination number, is more compact, with a K···K separation of 6.055(3) Å versus 6.165(4) Å in 4b . For comparison, the K···K distance in bent, polymeric potassium cyclopentadienyls is between 5.52 and 5.85 Å. 29b,32c,h,35b, …”

“…The K−C bond distances are 3.033(2) and 3.058(2) Å in 4a and 3.127(4) and 3.156(4) Å in 4b . In polymeric potassium cyclopentadienyls, the K−C distances range from 2.95 to over 3.30 Å, with the shortest K−C bond in each complex being between 2.952(2) and 3.074(7) Å. 29b,32c,h,35b, The potassium ions are closer to one of the boron atoms of each of the coordinating ligands. The two shorter K−B distances are 3.211(3) and 3.315(3) Å in 4a and 3.364(4) and 3.425(4) Å in 4b , while the longer K−B distances are 3.477(3) and 3.752(3) Å in 4a and 3.802(4) and 3.895(4) Å in 4b .…”

3 Alkali and alkaline-earth metals

“…85 4 Potassium, rubidium and caesium 86 The preparation of [M(C 5 Me 4 )SiMe 2 (CH 2 CHLCHCHCH 2 )] (M ~Li or K) and [K(C 5 Me 4 H)(dme)] ' has been described; the latter was crystallographically characterized. 87 EPR evidence for zwitterionic radicals with metal-ligand interactions has been obtained from cyclooctatriene-g 2 -ynyl salts of potassium and caesium. 88 Reaction of [MP(Ph)SiMe 2 Bu t ] (M ~Li or K) with PhCN affords the 1-aza-3-phosphaallyl compounds [M{P(Ph)C(Ph)NSiMe 2 Bu t }(L)] 2 (M ~Li, L ~thf; M ~K, L ~OEt 2 ).…”