Rhenium carbonyl complexes. Synthesis and characterisation of NN′-diarylamidines, R′NHC(R)NR′(R = H, Me, or Ph, R′= Ph or C₆H₄Me-p), and related carbamoyl derivatives

Abstract

NN'-Diarylacetamidines R'N HC( Me) N R', NN'-diarylbenzamidines R'N HC( Ph) N R' , and NN'-diarylformamidines R'NHC( H)NR' (R' = Ph or C6H4Me-p) react thermally or photolytically with [Re(CO),X] and/or [{Re(CO)4X},] (X = CI or Br) to afford air-stable, white complexes, [ Re(CO),{ R'NC( R) N H R'}X], containing monodentate amidine ligands. The corresponding lithioamidines (R = M e or Ph) gave white carbamoyl complexes [Re(CO),{CON(R')C(R)NR'}], which are converted thermally to NN'-bidentate [ Re(CO),{ R'NC( R) NR'}] and ortho-metallated [Re(CO),{R'NC(R)NHC6H3R"}{R'NC(R)NHR'}] (R" = H or Me). The latter complexes are also formed by further reaction of the carbamoyl complexes with the corresponding amidine. The carbamoyl complexes react with PPh3 to form [Re(C0)3(PPh3){ R'NC(R)NR'}]. Lithioamidines in excess react with [Re(CO),X] (X = CI or Br) complexes to give adducts formulated as Li+[Re(CO),{CON(R')C( R)NR'},] -. The new complexes are characterised, and structural data obtained by i.r. and n.m.r. spectroscopy. F -----1 * Calculated values in parentheses.

Photochemical Reaction of Ozone with 2-Iodopropane and the Four Polyfluoroiodoethanes C2F5I, CF3CH2I, CF2HCF2I, and CF3CFHI in Solid Argon at 14 K. FTIR Spectra of the Iodoso-Intermediates (Z−IO), the Iodyl-Intermediates (Z−IO2), and the Various Complexes (CH3)2CO···HI, CF3C(O)H···XI, CF2HC(O)F···IF, and CF3C(O)F···XI (Where X = H or F)

“…Infrared spectra recorded after Pyrex-filtered irradiation of argon matrices containing CF3CFHI and (a) 16 (λ > 350 nm) or Pyrex-filtered irradiation. [2][3][4] Also the 18 O-shifts are very close to that predicted for I-O, and the detection of bands for either the 16 O or 18 O isotopomer suggests the presence of a single oxygen atom in this species. Possibly the most diagnostic bands detected for this group, despite their weakness, are assigned to I-O and C-I stretches ( Table 2).…”

“…[2][3][4] In each case, the complex perturbs the photochemistry by allowing ozone to be dissociated after near-infrared irradiation (λ > 800 nm for 2-iodopropane and λ > 650 nm for the polyfluoroiodoethanes); this photodissociation occurs via a charge-transfer type mechanism, similar to that reported previously 4 in which an oxygen atom is transferred from ozone to the iodine atom of the iodinated alkane to form the iodosospecies. These bands (group 1) are detected after co-deposition of each of the five iodine-containing species and ozone in argon matrices and resemble the bands detected for the precursors isolated separately in argon (Tables 1, 6, 8, 10, and 12), except for small perturbations.…”

“…This group consists of medium bands assigned to C-O stretches detected at 968.7 and 961.5 cm -1 , having 18 O-shifts of 13.0 and 8.2 cm -1 , respectively. 4 The bands detected for group 5 were first detected after UVvis irradiation; Pyrex-filtered photolysis nearly quadrupled the intensities, while quartz-filtered irradiation increased the intensities by a further 50% ( Table 7). 4 The bands detected for group 5 were first detected after UVvis irradiation; Pyrex-filtered photolysis nearly quadrupled the intensities, while quartz-filtered irradiation increased the intensities by a further 50% ( Table 7).…”

A Facile Synthesis of a Push‐Pull Mixed‐Ligand Pd‐Dithiolene Complex Containing the Et2timdt Ligand (Et2timdt = Monoreduced Diethylimidazolidine‐2,4,5‐trithione)

“…[17] The dithiolato nature of mnt in 3 is also confirmed by its FT-Raman spectrum in the solid state: the CϭC stretching vibration of the mnt unit is found at 1485 cm 2Ϫ . [18] These experimental results are in agreement with a pushpull nature for 3, also supported by DFT calculations carried out on the corresponding model complex [Pd(H 2 timdt)(mnt)] (4). In this dithiolene, the HOMO and LUMO are π-type molecular orbitals (Figure 2): while the HOMO is mainly centred on the mnt dithiolato ligand and the terminal sulfur atom of the H 2 timdt trithione ligand, the LUMO has a remarkable contribution from the H 2 timdt ligand.…”

Electronic Spectra of Single-Crystal Maleonitriledithiolate Complexes of Iridium (I): [Ir(CO)2mnt] TBA (mnt ≡ [S2C2(CN)2]2-; TBA ≡ [(C4H9)4N] + )

“…Transition metal complexes with maleonitriledi thiolate (=m nt = [S2C2(CN)2]2") ligands and Ni(II), Pd(II), Pt(II) as central ions have been studied com prehensively by spectroscopic methods in the last years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The said complexes exhibit interesting properties, e.g.…”