Late transition metal oxo and imido complexes. 19. Phosphine-based dinuclear platinum(II) diamido, amido-hydroxo, oxo-amido, oxo-imido, diimido, and dihydrazido complexes

Citation
Jj. Li et al., Late transition metal oxo and imido complexes. 19. Phosphine-based dinuclear platinum(II) diamido, amido-hydroxo, oxo-amido, oxo-imido, diimido, and dihydrazido complexes, INORG CHEM, 38(7), 1999, pp. 1563-1572
Citations number
75
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
INORGANIC CHEMISTRY
ISSN journal
0020-1669 → ACNP
Volume
38
Issue
7
Year of publication
1999
Pages
1563 - 1572
Database
ISI
SICI code
0020-1669(19990405)38:7<1563:LTMOAI>2.0.ZU;2-C
Abstract
The platinum(II) amido-hydroxo and diamido complexes [(L2Pt)(2)(mu-NHR)(mu- OH)](BF4)(2) (1) (L = PPh3, R = Ph, p-tol, p-(BuC6H4)-C-t, p-NO2C6H4; L-2 = dppp, R = Ph, p-tol) and [L2Pt(mu-NHR)](2)(BF4)(2) (2) (L-2 = dppm, R = H, Ph, p-tol, NH2; L-2 = dppe, R = H, Ph, p-tol; L-2 = dppp, R = H, NH2; L-2 = dppb, R = NH2; L = PMe2Ph, R = H) are prepared from the reaction of [L2Pt (mu-OH)](2)(BF4)(2) with NH2R. [(PPh3)(4)Pt-2(mu-OH)(mu-NHR)](OTf)(2) (R = p-NO2C6H4) (1a), the triflate analogue of 1 (L = PPh3, R = p-NO2C6H4), is s imilarly prepared from [L2Pt(OH2)(2)](OTf)(2). Crystals of 1 . CH2Cl2 (L = PPh3, R = p-tol) from CH2Cl2/ether are monoclinic (P2(1)/n) with a = 16.331 (5) Angstrom, b = 23.908(5) Angstrom, c = 19.233(6) Angstrom, beta = 99.01( 1)degrees, and Z = 4. The cationic portion consists of two edge-shared squa re-planar Pt centers folded at the edge with cis-phosphines and bridging hy droxo and amido groups. LiN(SiMe3)(2), LiTPr2i, LiPh, or LiMe addition to 1 (L = PPh3, R = Ph, p-tol, p-(BuC6H4)-C-t) or 1a deprotonates the hydroxo g roup, forming the amido-oxo complexes [(L2Pt)(2)(mu-NHR)(mu-O)](BF4) (3) (L = PPh3, R = Ph, p-tol, p-(BuC6H4)-C-t) or [(PPh3)(4)Pt-2(mu-O)(mu-NHR)](OT f) (L = PPh3, R = p-NO2C6H4) (3a). Deprotonation of the diamido complexes 2 (L-2 = dppm, R = H, Ph, p-tol, NH2) with LiN(SiMe3)(2) yields [(dppm-H)Pt( mu-NHR)](2) (4) (R H, Ph, p-tol) or [(dppm-H)(2)Pt-2(mu-NHNH2)(2)Li(THF)(2) ]BF4 (5). Crystals of 4 (R = Ph) from CH2Cl2/ether are (183 K) orthorhombic (Pna2(1)) with a = 38.272(2) Angstrom, b = 9.2841(5) Angstrom, c = 15.0099 (7) Angstrom, and Z = 4. The structure consists of two edge-shared square-p lanar Pt centers folded at the edge with syn-bridging amido groups and chel ating dppm-H ligands. Crystals of 5 . 5THF from THF are (183 K) monoclinic (P2(1)/n) with a = 17.669(5) Angstrom, b = 31.884(3) Angstrom, c = 14.686(4 ) Angstrom, beta = 105.03(1)degrees, and Z = 4. The structure of the cation ic portion shows two edge-shared square-planar Pt centers folded at the edg e with syn-bridging NHNH2 groups and chelating dppm-H ligands. The NHNH2 gr oups bridge the Pt centers through the NH portion. The NH2 portions coordin ate to a Li(THF)(2)(+) group in a "tweezers" fashion resulting in tetrahedr al coordination about the Li atom. Further deprotonation of 4 with LiMe yie lds the anionic diimido complexes [(dppm-H)Pt(mu-NR)](2)(Li)(2) (6) (R = H, Ph, p-tol).