Dynamics and Counterion-Dependence of the Structures of Weakly Bound Ag+–P4S3 Complexes

Gold carbonyl cations and beyond: homoleptic gold(I) complexes with P4 and P4S3 and the half-sandwich cation [Au(C6H6)(CO)]. Chem Commun (Camb) 2024;60:5403-5406. [PMID: 38682872 DOI: 10.1039/d4cc01374c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Oxidation of Au0 with the synergistic Ag+/0.5 I2 system in the commercial organic solvent 1,2,3,4-tetrafluorobenzene led to the perfluoroalkoxyaluminate salt of the [Au(CO)2]+ cation known from superacid chemistry. This [Au(CO)2]+ salt proved to be an excellent 'naked' Au+-synthon yielding complex salts with [Au(η2-P4)2]+, [Au(η1-P4S3)2]+ and half-sandwich [Au(η2-C6H6)(CO)]+ cation.

Coordination Chemistry of P4 S3 and P4 Se3 towards the Iron Fragments [Fe(Cp)(CO)2 ]+ and [Fe(Cp)(PPh3 )(CO)]. Chemistry 2019;25:12159-12168. [PMID: 31287589 PMCID: PMC6771638 DOI: 10.1002/chem.201902339]

The complexes Ag(L)n [WCA] (L=P4 S3 , P4 Se3 , As4 S3 , and As4 S4 ; [WCA]=[Al(ORF )4 ]- and [F{Al(ORF )3 }2 ]- ; RF =C(CF3 )3 ; WCA=weakly coordinating anion) were tested for their performance as ligand-transfer reagents to transfer the poorly soluble nortricyclane cages P4 S3 , P4 Se3 , and As4 S3 as well as realgar As4 S4 to different transition-metal fragments. As4 S4 and As4 S3 with the poorest solubility did not yield complexes. However, the more soluble silver-coordinated P4 S3 and P4 Se3 cages were transferred to the electron-poor Fp+ moiety ([CpFe(CO)2 ]+ ). Thus, reaction of the silver salt in the presence of the ligand with Fp-Br yielded [Fp-P4 S3 ][Al(ORF )4 ] (1 a), [Fp-P4 S3 ][F(Al(ORF )3 )2 ] (1 b), and [Fp-P4 Se3 ][Al(ORF )4 ] (2). Reactions with P4 S3 also yielded [FpPPh3 -P4 S3 ][Al(ORF )4 ] (3), a complex with the more electron-rich monophosphine-substituted Fp+ analogue [FpPPh3 ]+ ([CpFe(PPh3 )(CO)]+ ). All complex salts were characterized by single-crystal XRD, NMR, Raman, and IR spectroscopy. Interestingly, they show characteristic blueshifts of the vibrational modes of the cage, as well as structural contractions of the cages upon coordination to the Fp/FpPPh3 moieties, which oppose the typically observed cage expansions that lead to redshifts in the spectra. Structure, bonding, and thermodynamics were investigated by DFT calculations, which support the observed cage contractions. Its reason is assigned to σ and π donation from the slightly P-P and P-E antibonding P4 E3 -cage HOMO (e symmetry) to the metal acceptor fragment.

A Ferrocenyl-Backboned Unsymmetric O,C-Coordinating Ligand and Its Tin Derivatives

The syntheses of the phosphonyl-substituted ferrocenyl stannane Fe[{η (5)-C5H3-1-SnPh3-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (1) and its iodine derivative Fe[{η (5)-C5H3-1-SnPh2I-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (2) are reported. The syntheses of the corresponding salts Fe[{η (5)-C5H3-1-SnPh2-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}]X (3, X=Al{OC(CF3)3}4, 4, X=ClO4, 5, X=HgI3), respectively, are also described. The compounds are characterized by elemental analyses, (1)H, (13)C, (31)P, (119)Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and, except for 4 and 5, single-crystal X-ray diffraction analyses.