Structural Characterization of Representative d⁷, d⁸, and d⁹ Transition Metal Complexes of Bis(o-carborane)

Abstract

This paper presents the first crystallographically characterized, contiguous series of 4-coordinate transition metal compounds having a common organometallic ligand set and differing only in the identity and oxidation state of the metal. This series spans from d7 to d9 with overlapping examples for d8. M = Co(II), Ni(II), Cu(III), and Cu(II).

Synthesis, structural characterization, and reactivity of late transition-metal complexes bearing linked cyclopentadienyl–carboranyl ligands

“…They are also similar to the 2.102(6) Å in [Ni(h 5 -C 5 H 5 )(PPh 3 )C≡CCHO], 9 to the 2.182(3) Å in [(h 5 -1-TMS-C 9 H 5 )NiCl(PPh 3 ), 10 to the 2.114(7) Å in (h 5 :h 1 -C 5 H 4 CH 2 CH 2 NMe 2 )Ni(C 12 H 8 N), 11 and to the 2.098(9) Å in [(h 5 -C 5 H 4 CH 2 CH 2 NMe 2 )Ni(dmpe)][PF 6 ]. 12 The metal -cage carbon distances (M-C cage ) between 1.95 and 2.01 Å for 4-8 are comparable to the 1.998(9)-2.013(9) Å in [Ni{(C 2 B 10 H 10 ) 2 } 2 ] 2-, 13 17 and to the 2.134(1) Å in Cp*Ni(PPh 3 )(CH 2 COt-Bu). 18 …”

“…For complexes 5, 7, and 8, the 1 H and 13 C NMR spectra showed the presence of the ligand and coordinated PPh 3 with an 1:1 molar ratio. Their 11 B NMR spectra exhibited the same 2:3:5 pattern.…”

Sulfur, tin and gold derivatives of 1-(2′-pyridyl)-ortho-carborane, 1-R-2-X-1,2-C2B10H10(R = 2′-pyridyl, X = SH, SnMe3or AuPPh3)

“…The pyridine group tilts slightly toward the tin atom, apparently due to the Sn···N attraction, but the tilt is small with the B(12)-C(1)-C(12) angle in 6 being 176.6(3)º. 12 Of more relevance to 6, perhaps, is the crystal structure of a dimeric carborane assembly consisting of two 1-Me 2 NCH 2 -2-SnMe 2 -1,2-C 2 B 10 H 10 moieties linked by a Sn-Sn bond. 6 This was made from 1, BuLi and Me 2 SnBr 2 followed by reduction with sodium metal.…”

“…Copper carboranes are apparently more stable when two or more cage C-Cu bonds are present. 11,12 The only crystal structures of ortho-carboranes with cage C-Cu single bonds are found in salts of [{(C 2 B 10 H 10 ) 2 } 2 Cu] -and [{(C 2 B 10 H 10 ) 2 } 2 Cu] 2-where the copper atom is bonded to four cage carbons with C-Cu bond lengths between 2.01 and 2.07 Å. 12 Here, we report the synthesis, spectroscopic and structural characterisation of three new derivatives 1-(2'-pyridyl)-ortho-carborane 3.…”

“…11,12 The only crystal structures of ortho-carboranes with cage C-Cu single bonds are found in salts of [{(C 2 B 10 H 10 ) 2 } 2 Cu] -and [{(C 2 B 10 H 10 ) 2 } 2 Cu] 2-where the copper atom is bonded to four cage carbons with C-Cu bond lengths between 2.01 and 2.07 Å. 12 Here, we report the synthesis, spectroscopic and structural characterisation of three new derivatives 1-(2'-pyridyl)-ortho-carborane 3. One of these is the 2-mercapto derivative (5), which we believe to be the first derivative of ortho-carborane containing a mercapto group -SH to be structurally characterised.…”