Tetrametallic divalent samarium cluster hydride and dinitrogen complexes

Reduction of trivalent samarium complexes obtained Fia reaction of SmCl3(TH F)(3) with the disodium salt of the dipyrrolide dianion [R2C(H3C4N)(2)](2-) (R = Ph, 1/2 -(CH2)(5)-) were carried out with sodium in THF and under nit rogen. The tao reactions respectively yielded the tetranuclear divalent hyd ride {Na(THF6}{([Ph2C(C4H3N)(2)]Sm)(4)(H)(THF)(2)} (1) and the tetranuclear dinitrogen complex {[(CH2)(5)C(C4H3N)(2)]Sm}(4)(THF)(2)(mu-N-2)[Na(THF)](2 ). 2THF (2). Transmetalation of [(Me3Si)N](2)Sm(THF)(2) with 1,1-dipyrrolyl cyclohexane afforded the dinitrogen complex {[(CH2)(5)C(C4H3N)(2)]Sm}(4)(mu -N-2). 0.5THF (3). Despite the different oxidation states of 2 and 3 and th e presence/absence of alkali-metal cation the two complexes display the sam e N-N distance.