W. L. Groeneveld

Triphenylphosphine oxide complexes of metal(II) tetrafluoroborates

Abstract A number of new complexes containing triphenylphosphine oxide is reported. The compounds have the general formula M(TPPO)n(BF4)2, in which M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd (n = 4) and Co,Ni (n = 5). Thet are characterized and identified by chemical analysis and physical measurements. It is shown that the tetrakis cobalt and zinc compounds contain tetrahedrally solvated metal ions and that the pentakis cobalt and nickel complexes contain octahedrally coordinated metal ions. The measurements on the tetrakis manganese, nickel and cadmium compounds can best be correlated with a basically square pyramidal structure. For the copper complex a square planar surrounding of the metal ions is suggested. The compounds of magnesium, calcium and iron are believed to contain distorted octahedrally coordinated metal ions. The interesting behaviour of the nickel complexes on heating is discussed and it is shown that in this way a tetrahedral modification can be obtained.

The coordination chemistry of phosphoryl compounds containing the −N(CH3)2 group—IX[1]: Mössbauer spectra of some iron complexes of hexamethylphosphoramide and nonamethylimidodiphosphoramide

Abstract Mossbauer spectra for high-spin iron compounds of the type Fe(ligand) p (anion) q with hexamethylphosphoramide and nonamethylimidodiphosphoramide as ligands ( p = 1–4) and ClO 4 − , BF 4 − , Cl − , Br − , I − , NO 3 − and NCS − as anions ( q = 2, 3), have been obtained at 77°K and, for two compounds, at room temperature. The values for the chemical shift and the quadrupole splitting are compared with literature data. It is shown that Mossbauer spectroscopy can be very helpful in elucidating the structures of and bonding in iron(II) and iron(III) complexes. The high values for the centre shifts of the bivalent solvates suggest that in these complexes the bonding between the ligands and the metal ions is essentially electrovalent.

The coordination Chemistry of carbonyl compounds

Abstract The solvating properties of a number of carbonyl compounds have been investigated. The ligands used are acetaldehyde, propionaldehyde, benzaldehyde, methylformate, formamide, N,N-dimethylformamide, acetone, chloroacetone, butanone, acetophenone, ethylacetate, acetamide, N,N-dimethylacetamide, acetanilide, chloroacetamide, trimethylacetamide, benzamide, nicotineamide, 2-nitrobenzamide, 2,6-dichlorobenzamide, urethane, urea and dimethylcarbamoylchloride. The complexes are characterized and identified by means of chemical analysis and physical measurements. Ligand-field parameters are reported for the solvates of cobalt(II) (in the solid state) and nickel(II) (both in the solid state and in nitromethane solution). A (linear) correlation between the ligand-field parameters and parameters describing certain electronic effects of the substituents R1 and R2 in R1R2CO molecules, has been investigated; it is shown that no correlation exists.

The coordination chemistry of trimorpholinophosphine oxide

Abstract A number of new complexes containing trimorpholinophosphine oxide (MORPO) is reported. The compounds have the general formula M(MORPO)n(anion)2, where M  Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn and Cd, n = 1 2 –4 , and anion stands for BF4−, NO3−, NCS−1, Cl−, Br− and I−. The compounds are identified and characterized by chemical analyses and physical measurements. It is shown that the ligand coordinates via the phosphoryl oxygen atom, yielding tetrahedrally and octahedrally surrounded metal ions. The ligand properties of MORPO are compared with those reported for other phosphoryl ligands. It is concluded that, for solvates, the number of ligands per metal ion is determined by the steric properties of the ligands and, for adducts, also by the type of anion. The actual type of coordination is influenced by the electronic configuration of the metal ions (for solvates) and by the type of anion (for adducts).

The coordination chemistry of phosphoryl compounds containing the-N(CH3)2 group—X[1]: Complexes of hexamethylphosphoramide and nonamethylimidodiphosphoramide with metal nitrites

Abstract A number of new nitrite complexes of the ligands hexamethylphosphoramide (HMPA) and nonamethylimidodiphosphoramide (NIPA) is reported. The complexes have the general formula MLp(NO2)q, where M = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd (q = 2) and Cr, Fe (q = 3), L = HMPA, NIPA and p = 1–4. A number of HMPA complexes which are already known, were reprepared. The compounds are characterized and identified by chemical analyses and physical measurements. It is shown that with the exception of M(NIPA)3(NO2)q(M = Mg, Ca, q = 2, and M = Fe, q = 3), the nitrite ions are coordinated to the metal ions. With the aid of i.r. and ligand-field spectroscopy, the mode of coordination of the nitrite ions is established. The results for the reprepared HMPA complexes appeared to deviate considerably from previous assignments. It is concluded that the nitrite ion behaves very similar to the nitrate ion in complexes of the ligands HMPA and NIPA.

The Coordination Chemistry of Phosphoryl Compounds Containing the — N(CH3)2 Group, Part VIII

A number of new solvates and adducts containing bisphenyldimethylaminophosphine oxide is reported. The solvates have the general formula M[(C6H5)2P(O)N(CH3)2]42+(anion-)2, in which M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn and Cd, and the anions are ClO4- and BF4-. The adducts have the general formula M[(C6H5)2P(O)N(CH3)2]2Cl2, where M stands for the same series of metals. The compounds are characterized and identified by chemical analyses and physical measurements. Ligand-field and vibrational spectra have been investigated; values for the ligand-field parameters are reported. It is concluded that coordination takes place via the oxygen atom of the ligand. X-ray powder patterns were used in combination with ligand-field spectra to deduce the coordination around the metal ions. The interesting behaviour of the nickel (II) chloride adduct upon heating is discussed and it is shown that both a square pyramidal and a tetrahedral modification exists.

Complexes of Bismethyl-imido-triphosphoric-acid-pentakis-dimethyl-amide (TRIPA), a New Tridentate Ligand

A number of new complexes containing TRIPA, chemical formula [ (CH3) 2N]2 P (O) N (CH3)P (O) [N (CH3) 2] N (CH3) P (O) [N (CH3) 2] 2, is reported The compounds have the general formula M (TRIPA) n (anion) p, where M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd (p = 2) and Al, Fe (p = 3), n=1,2 and anion stands for BF4⁻, [B (C6H5)4]⁻, NO3⁻ and Cl⁻. They are characterized and identified by chemical analysis and physical measurements. It is shown that the bis-compounds contain octahedrally solvated metal ions, the ligand acting as a tridentate phosphoryl donor. Electron paramagnetic resonance measurements show some distortion of the octahedrons. The mono-compounds with the nitrate anion probably possess a fivecoordinated structure whereas the chloride complexes are probably dimeric. The occurrence of more than one geometric isomer for the group [M (TRIPA) 2] P* is discussed. It is concluded that the s-facial and u-facial isomers may occur; a possible connection with the size of the metal ions is indicated. The mer form is rejected because of steric requirements.