Homoleptic tetraazaphenanthrene-based copper(I) complexes:Synthesis, spectroscopic characterization, crystal structures and computational studies

Three new Cu(I) complexes containing bidentate N^N donor ligands with the general formula [Cu(N^N)2][PF6] (N^N = 2,3-diphenyl-6,7-di-p-tolyl-1,4,5,8-tetraazaphenanthrene (L1), 2,3-diphenyl-6,7-di(2-thienyl)-1,4,5,8-tetraazaphenanthrene (L2), and 2,3-diphenyl-6,7-di-p-fluorophenyl-1,4,5,8-tetraazaphenanthrene (L3), were prepared by the reaction of [Cu(CH3CN)4][PF6] with two equivalents of the N^N ligand. Single-crystal X-ray diffraction analysis confirmed that in each complex the metal displays a distorted tetrahedral geometry surrounded by the four N atoms of the two sterically hindered substituted tetraazaphenanthrene (TAP) ligands. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT), calculations were used to study the ground state properties and interpret the absorption spectra for these Cu(I) complexes. The calculations show that the lowest-energy excitations of all complexes are dominated by dπ(Cu) → π∗(L), metal-to-ligand charge transfer, (MLCT) excitations. Electronic difference density maps (EDDMs) were calculated, indicating the change of electron density in the singlet excited states. The degree of filling of the coordination sphere (G parameter) by the ligands was calculated taking into account the ligand–ligand overlap, and compared to the related bis(2,9-disubstituted phenanthroline) Cu(I) complexes

Structural effects in lithiocuprate chemistry:the elucidation of reactive pentametallic complexes

TMPLi (TMP=2,2,6,6-tetramethylpiperidide) reacts with Cu(I) salts in the presence of Et(2)O to give the dimers [{(TMP)(2)Cu(X)Li(2)(OEt(2))}(2)] (X=CN, halide). In contrast, the use of DMPLi (DMP=cis-2,6-dimethylpiperidide) gives an unprecedented structural motif; [{(DMP)(2)CuLi(OEt(2))}(2)LiX] (X=halide). This formulation suggests a hitherto unexplored route to the in situ formation of Gilman-type bases that are of proven reactivity in directed ortho cupration

Thermal and photochemical control of nitro-nitrito linkage isomerism in single-crystals of [Ni(medpt)(NO₂)(η²-ONO)]

The known complex [Ni(medpt)(η1-NO2)(η2-ONO)] 1 (medpt = 3,3′-diamino-N-methyldipropylamine) crystallises in the monoclinic space group P21/m with 1.5 molecules in the asymmetric unit with two different η1-NO2 ligand environments in the crystal structure. At 298 K the molecule (A) sitting in a general crystallographic site displays a mixture of isomers, 78% of the η1-NO2 isomer and 22% of an endo-nitrito–(η1-ONO) form. The molecule (B) sitting on a crystallographic mirror plane adopts the η1-NO2 isomeric form exclusively. However, a variable temperature crystallographic study showed that the two isomers were in equilibrium and upon cooling to 150 K the η1-ONO isomer converted completely to the η1-NO2 isomer, so that both independent molecules in the asymmetric unit were 100% in the η1-NO2 form. A kinetic analysis of the equilibrium afforded values of ΔH = −9.6 (±0.4) kJ mol−1, ΔS = −21.5 (±1.8) J K−1 mol−1 and EA = −1.6 (±0.05) kJ mol−1. Photoirradiation of single crystals of 1 with 400 nm light, at 100 K, resulted in partial isomerisation of the η1-NO2 isomer to the metastable η1-ONO isomer, with 89% for molecule (A), and 32% for molecule (B). The crystallographic space group also reduced in symmetry to P21 with Z′ = 3. The metastable state existed up to a temperature of 150 K above which temperature it reverted to the ground state. An analysis of the crystal packing in the ground and metastable states suggests that hydrogen bonding is responsible for the difference in the conversion between molecules (A) and (B)

New di-ferrocenyl-ethynylpyridinyl triphenylphosphine copper halide complexes and related di-ferricenyl electro-crystallized materials

Three di-ferrocenyl-ethynylpyridinyl copper complexes have been synthesised and CV measurements made.</p

Photolytic Preparation Of (benzylideneacetone)carbonylphosphineiron(0) Complexes. The Molecular Structures Of Fe(co)2(pet3)(bda) And Fe(co)2(pphme2)(bda) (bda Benzylideneacetone)

The (benzylideneacetone) carbonylphosphine iron(0) complexes, Fe(CO)2L(bda), Fe(CO)L′2(bda) and Fe(CO)(dpe)(bda)(L = PEt3, PPhMe2, Me; L′ = PPhMe2, PPh2Me; dpe = [Ph2P(CH2)]2) have been prepared by irradiating the corresponding tetracarbonylmonophosphine iron(0), tricarbonyldiphosphine iron(0) or tricabonyl-1,2-bis (diphenylphosphine)ethane iron(0) complexes in benzene in the presence of benzylideneacetone. The X-ray crystal structures of the complexes with L = PEt3 (A) and PPhMe2 (B) have been determined, and show that the Fe atom adopts a distorted octahedral coordinated geometry in which three of the sites are occupied by the bda ligand. The bond parameters in the bda ligand suggest that this coordinated group is intermediate between its ground and first excited states. The complex Fe(CO)2(PEt3(bda) crystallises in the monoclinic space group P2l/c with a 10.203(3), b 12.964(4), c 16.960(6) Å, β 120.00(2)°, and Z = 4. The structure was solved by a combination of Patterson and Fourier diffence techniques and refined by blocked full matrix least squares to R = 0.035 for 3351 unique observed diffratometer data. The complex Fe(CO)2(PPhMe2)(bda) also crystallises in space group P2l/c, with a 8.134(3), b 21.394(8), c 11.658(5) Å, β 108.18(2)° and Z = 4. The structure was solved and refined as above to R = 0.036 for 3498 diffractometer data. The IR and 1H NMR data for all the complexes studied agree with the observed structures. © 1983.2561111124Otsuka, Yoshida, Nakanima, (1967) Inorg. Chem., 6, p. 20tom Dieck, Bock, (1968) J. Chem. Soc. Chem. Commun., p. 678Brodie, Johnson, Josty, Lewis, Some ?-hetero-1,3-diene complexes of iron carbonyl (1972) Journal of the Chemical Society, Dalton Transactions, p. 2031Liebfritz, tom Dieck, Intramolekularer ligandenaustausch in einkernigen heterodien-eisentricarbonylkomplexen (1976) Journal of Organometallic Chemistry, 10, p. 255Vessieres, Dixneuf, (1974) Tetrahedron Lett., p. 1499Vessieres, Dixneuf, (1976) J. Organomet. Chem., 108, p. C5Howell, Johnson, Lewis, (1972) J. Organomet. Chem., 39, p. 326Johnson, Lewis, Stephenson, Vichi, Preparation and reactions of triphenylphosphine and triphenyl phosphite complexes of (benzylideneacetone)dicarbonyliron(0) (1978) Journal of the Chemical Society, Dalton Transactions, p. 369Henderson, Streuli, (1960) J. Amer. Chem. Soc., 82, p. 5791Tolman, (1977) Chem. Revs., 77, p. 313Pearson, Raithby, Diene?metal ? bonding. Some unexpected effects of Group 5 donor ligands on carbon-13 nuclear magnetic resonance parameters and X-ray crystal structures (1981) Journal of the Chemical Society, Dalton Transactions, p. 884Kruger, Barnett, Brauer, Koerner von Gustorf, Grevels, (1978) The Organic Chemistry of Iron, , I. Fischler, Academic Press, New York, ch. 1 and refs. therein;Pearson, Raithby, Organoiron complexes in organic synthesis. Part 4. Direct ring connection between highly substituted centres. A potential approach to trichothecane synthesis (1980) Journal of the Chemical Society, Perkin Transactions 1, p. 395Churchill, Chang, (1977) Inorg. Chem., 129, p. 105Mills, Robinson, (1960) Proc. Chem. Soc., p. 421Mills, Robinson, Studies of some carbon compounds of the transition metals. IV. The structure of butadiene irontricarbonyl (1963) Acta Crystallographica, 16, p. 758Chaudari, Pauson, (1966) J. Organomet. Chem., 5, p. 73Edwards, Howell, Johnson, Lewis, (1974) J. Chem. Soc., Dalton Trans., p. 2107(1974) International Tables for X-ray Crystallography, 4. , Kynoch Press, BirminghamSHELX 76, G M Sheldrick (1976) A molecular structure determination program package, , Cambridg

Synthesis And Structural Characterization Of The Phosphido Cluster [ir4h(co)10(μ-pph2)] And Its Facile Carbonyl Substitution Reactions With A Series Of Phosphines And Phosphites

The tetranuclear cluster [Ir4H(CO)10(μ-PPh2)] 1 is formed from [Ir4(CO)11(PPh2)] 2 by deprotonation, which yields [Ir4(CO)10(μ-PPh2)]- 3, followed by protonation of the anion. It has been fully characterized by an X-ray analysis, and exhibits a tetrahedral arrangement of metal atoms with the three basal edges bridged by a phosphido, a hydrido and a carbonyl ligand. Both 1 and 3 undergo facile carbonyl substitution reactions with phosphites and phosphines L [PPh3, PPhMe2, P(OPh)3 or P(C6H4X-4)3 (X = F, Cl, Me, 4-Ome or 2-OMe)] to give [Ir4H(CO)9L(μ-PPh2)] 4a-4h and [Ir4(CO)9L(μ-PPh2)]- 5a-5h respectively, the latter being converted into the corresponding hydride derivatives by protonation. Further substitution of a CO in 4a-4h affords [Ir4H(CO)8L2(μ-PPh2)] 6a-6h. An X-Ray analysis of [Ir4H(CO)9(PPh3)(μ-PPh2)] 4a shows that carbonyl substitution has occurred at a basal Ir atom which is not bridged by the phosphido ligand.121797180