Iii Transition Metal Promoted Routes To Dithiolenes
A. Addition of Electrophilic Alkynes to Metal Sulfides Metal per- and polysulfido complexes react with electrophilic alkynes to give dithiolenes. The readily available diester DMAD is most commonly employed in this reaction 12, 188, 208-222 . Other electrophilic alkynes that have been used in this context are C2 CF3 2 175, 223, 224 , HC2CO2Me 189 , C2 C O Ph 2 225 , and C2 C O NH2 2 12, 226 . Still more elaborate alkynes have been employed in the synthesis of pterin-related dithiolenes 217, 227...
Info Ybu
With rich luminescent properties, long-lived CT excited states and a variety of bimolecular photochemical reaction pathways, the mixed-ligand square-planar diimine dithiolene complexes of d8 metal ions show great promise for solar-energy conversion, as luminescent probes or in photocatalytic applications. Complexes of this type have also received attention for the nonlinear optical properties, such as second harmonic generation, related to the MMLL' CT excited state 14, 129 . III. TETRAHEDRAL...
Info Hwb
Figure 8. Frequencies of the principal IR component of v C N in M S2C2 CN 2 2 1 ,2 ,3 complexes M Mn, Fe, Co, Ni, Cu, Zn, Pd, Pt, Au as a function of charge on the complex. Reproduceed by permission of the Royal Society of Chemistry 20 . v C N frequency in IR spectroelectrochemical studies 20 . The C N stretch is only weakly coupled to other vibrations. Consequently, the v C N frequency provides a direct monitor of p electron density on the dithiolene chelate ring and thereby is an indirect...
i x
determined solely by the ligand coefficients in Cxy. This results in a c2 c3 ratio of 2.6-6.0, providing an estimate of anisotropic in-plane vs. out-of-plane covalency contributions to Mo-dithiolene bonding in the ground-state CXy highest occupied molecular orbital HOMO wave function. The results of these recent detailed spectroscopic studies on simple L-N3 MoO dithiolene complexes 19, 23 have allowed the assignment of low-energy dithiolene Mo CT transitions Table III , which are the dominant...
SH Lle
Figure 6. Hahn's methodology to bis benzenedithiolates . from 1,2-C6H4Cl2, to give the versatile nucleophile 3-LiC6H3-1,2- S-i'-Pr 2 43 . This revised metalation procedure was employed in the synthesis of the ethylene-linked dithiolene 1,2-C2H4 3-C6H3-1,2- SH 2 2, which forms bimetallic complexes with a staircase-like structure Fig. 7 . Figure 7. Structure of Ni2 S2C6H3 2C2H4 2 4 40 . Figure 7. Structure of Ni2 S2C6H3 2C2H4 2 4 40 . 3. Heterocyclic and Heteroatomic Dithiolates Heterocyclic...
References 1
1. R. Eisenberg, Prog. Inorg. Chem., 12, 295 1970 . 2. J. A. McCleverty, Prog. Inorg. Chem., 10, 49 1968 . 3. R. P. Burns, and C. A. Mcauliffe, Adv. Inorg. Chem. Radiochem., 22, 303 1979 . 4. U. T. Muller-Westerhoff and B. Vance, in Comprehensive Coordination Chemistry, Vol. 2, G. Wilkinson, R. D. Gillard, and J. A. McCleverty, Eds., Pergamon Press, Oxford, 1987, p. 595. 5. F. H. Allen and O. Kennard, Chemical Design Automation News, 8, 31 1993 . 6. L. J. Farrugia, J. Appl. Crystallogr, 32, 565...
Info Fyj
the Pt complex than the Ni complex. The lack of IPCT in solutions without an excess of MV2 suggests that the forward ET occurs from a contact ion-pair complex. An observation that the decay of the transient follows second-order kinetics k 1 x 1010 M-1 s supports a mechanism with back ET occurring from a solvent separated ion pair that must first recombine by diffusion. This mechanism is summarized in Scheme 1. Similar IPCT photochemistry is observed for salts involving other organic acceptors,...
CO Snr
M S2C2R2 2 CO PR'3 R' Bu, f-Bu Figure 14. Selected reactions of M S2C2R2 2 CO 2 and related derivatives M Mo, W 198-200 . this complex has not been examined see related work on dithiaoxamide complexes of Mo Section II.G . After a long hiatus, the dithiolene-transfer reaction involving Ni S2C2R2 2 was rejuvenated by Holm and co-workers 198 who sought new routes to bis dithiolene complexes of molybdenum and tungsten as models for metalloen-zymes. As discussed above, a synthetic challenge in the...
Info Yre
allowed electronic transition with A-term resonance enhancement of Ag modes that mimic the distortion in the electronic excited state 8 . Hence, the RR data were initially interpreted in terms of the lAg 1B2u metal-to-ligand chargetransfer MLCT assignment for the 476-nm absorption band 9 . Moreover, the strong enhancement of the Ag v C N mode demonstrates extensive delocali-zation of the dithiolene molecular orbitals extending over the CN group. In contrast to the Ag modes, which have...
WW SiP b
Figure 41. Qualitative MO energy diagram for MoO bdt 2 1 . Here, b represents a bonding MO and nb represents a non-bonding MO. Adapted from 106 . ligand, resulting in very large splittings within the t2g orbital set for the latter. Therefore, the dxzyz orbitals in oxo-metallo-bis dithiolenes are unoccupied, and higher oxidation states are favored by the metal. Furthermore, the low-energy CT transitions are found to be L M instead of intraligand in nature and the M O bonding scheme presented in...
Contents 1
II. SYNTHESIS FROM PREFORMED ALKENEDITHIOLATES, 1,2-DITHIONES, OR THEIR EQUIVALENT 4 A. From Benzenedithiol and Related Derivatives 4 2. Linked Bis benzenedithiolate Complexes 8 3. Heterocyclic and Heteroatomic Dithiolates 10 B. From 1,2-Alkenedithiolates 10 1. Via Reductive Dealkylation 10 2. By Base Hydrolysis of Dithiocarbonates Dithiole-2-ones and Related Derivatives 11 C. From Selected 1,2-Alkenedithiolate Dianions 15 dmit2 15 2. Inorganic Dithiolates Related to dmit2 17 3....
Info App
Tetraalkylammonium tetraarylphosphonium
Tetrahedron Konarewski
1. N. Svenstrup and J. Becher, Synthesis, 215 1995 . 2. A. E. Pullen and R.-M. Olk, Coord. Chem. Rev., 188, 211 1999 . 3. N. Robertson and L. Cronin, Coord. Chem. Rev., 227, 93 2002 . 4. D. C. Rees, Y. L. Hu, C. Kisker, and H. Schindelin, J. Chem. Soc., Dalton Trans., 3909 5. S. J. N. Burgmayer, Prog. Inorg. Chem., 52, 0000 2003 . 6. C. Kisker, H. Schindelin, and D. C. Rees, Ann. Rev. Biochem., 66, 233 1997 . 7. M. J. Rudolph, M. M. Wuebbens, K. V. Rajagopalan, and H. Schindelin, Nat. Struct....