Antiferromagnetic complexes with metalmetal bonds

The Unusual Paramagnetic Mixed-Metal Carbonyl Chalcogenide Clusters: [E2Cr2Fe(CO)10]2- (E = Te, Se)

“…and tellurium congeners. The related sulfur-containing complexes with carbonyl ligands are limited to [SFeCr-(CO) 4 Cp] 2 ,13 {S 4 Cr 2 Fe 2 (CO) 6 Cp 2 (S t Bu)}Fe,14 and S 2 Cr 2 Fe-(CO) 3 (S t Bu)Cp 2 .…”

“…Further, the mixed chromium−iron carbonyl clusters with the heteronuclear metal−metal bonds are observed only in their sulfur analogue but not in the selenium and tellurium congeners. The related sulfur-containing complexes with carbonyl ligands are limited to [SFeCr(CO) 4 Cp] 2 , {S 4 Cr 2 Fe 2 (CO) 6 Cp 2 (S t Bu)}Fe, and S 2 Cr 2 Fe(CO) 3 (S t Bu)Cp 2 . The limited number of mixed chromium−iron or chromium-containing carbonyl clusters compared to their Mo analogues may be related to the lability of Cr…”

-initiated N–N bond cleavage in a thiotetrazole ligand in a cyclopentadienylchromium complex

“…We have previously postulated such pathways for the formation of complex molecular structures from similar reactions of compounds of CpCr(dithiocarbamate) [5] and CpCr(benzothiazole) [6] and of CpCr systems containing P,S-ligands [20]. Complexes 9-13 have all been previously characterized [1,16,[21][22][23]. The high yield of [CpCr(CO) 2 ] 2 (9), the decarbonylation derivative of 1 [21] is indicative of the relative difficulty of N-N bond scission in this complex.…”

“…The high yield of [CpCr(CO) 2 ] 2 (9), the decarbonylation derivative of 1 [21] is indicative of the relative difficulty of N-N bond scission in this complex. Cubane complexes 12 and 13 are isolated thermolytic derivatives of [CpCr(CO) 2 ] 2 S (10) [16]; Cp 4 Cr 4 S 2 O 2 (11) [23] is also in all likelihood one of the thermolysis products of 10, by inference from the formation of its Se analogue from thermal degradation of the Se analogue of 10 [24]. The combined substantial yield (ca.…”

“…9-13. These complexes were identified by comparison of their 1 H NMR and mass spectral data with published values [16,[21][22][23].…”