Tamara A. Ulibarri

Synthesis and X-ray crystallographic characterization of the decamethylsamarocene solvates (C5Me5)2Sm(OC5H8)2 and (C5Me5)2Sm(OC5H10)

The bis(dihydropyran) and mono(tetrahydropyran) solvates of (C 5 Me 5 ) 2 Sm have been prepared by displacing THF from (C 5 Me 5 ) 2 Sm(THF) 2 and have been studied by X-ray diffraction. (C 5 Me 5 ) 2 Sm(OC 5 H 8 ) 2 crystallizes from C 5 H 8 O in space group P 2 1 / c with a = 11.819(6), b = 14.192(10), c = 17.838(6) A,β = 95.26(4)° and D calc = 1.313 g cm −3 for Z = 4. Least-squares refinement on the basis of 3168 observed reflections led to a final R value of 0.047. (C 5 Me 5 ) 2 Sm(OC 5 H 10 ) crystallizes from hexane in space group P 2 1 / a a with a = 14.900(5), b = 16.263(7), c = 10.732(3) A, β = 70.32(2)° and D calc = 1.376 g cm −3 for Z = 4. Least-squares refinement of 3660 observed reflections led to a final R value of 0.046. Structural variations in the (C 5 Me 5 ) 2 Sm(ether) x series where x = 0, 1 and 2 are analysed.

Relative reactivity of decamethylsilicocene and decamethylsamarocene : reduction of (C5Me5)2SiCl2 by Sm(II) reagents

Recently two remarkable, strongly reducing decamethylmetallocenes have been described: (C 5 Me 5 ) 2 Si (1) and (C 5 Me 5 ) 2 Sm (2). Decamethylsilicocene was the first π complex with silicon as a central atom and decamethylsamarocene was the first f-element complex with just two cyclopentadienyl rings as the only ligands, i.e., the first f-element analog of ferrocene. We were interested in examining the relative reactivities of these two divalent species and decided to examine the reduction of (C 5 Me 5 ) 2 SmCl(THF) by 1 and the reduction of (C 5 Me 5 ) 2 SiCl 2 by 2

Europium-151 Mössbauer effect study of relaxation in two bi(pentamethylcyclopentadienyl) europium(II) complexes

Europium-151 Mössbauer spectra of two bis(pentamethylcyclopentadienyl) europium complexes have been recorded at 78K. The broad spectra with linewidths of 14.2 and 11.6 mm/s, and with isomer shifts of −12.5 and −12.8 mm/s, relative to EuF3 may be understood in terms of spherical relaxation of the effective hyperfine field.