E. S. Vikulova

Volatile iridium(I) complexes with β-diketones and cyclooctadiene: syntheses, structures and thermal properties

Abstract A series of volatile mixed-ligand iridium(I) complexes [Ir(cod)(L)] (cod = cyclooctadiene-1,5, L = R1C(O)CHC(O)R2, R1 = CF3, R2 = CF3 – hfac 1, Me – tfac 2; tBu – ptac 3, Ph – btfac 4, R1 = R2 = Me – acac 5; tBu – thd 6) was synthesized and investigated in terms of usage in metal-organic chemical vapor deposition processes. Compounds 3 and 4 were obtained for the first time. All compounds were investigated by elemental analysis, NMR spectroscopy, thermogravimetry, and mass spectrometry. Crystal structures of 2–4 and 6 were determined by single-crystal XRD. The influence of β-diketonate ligand on the thermal properties of complexes in condensed and gas phase was revealed. The following volatility order was arranged: L = hfac 1 > tfac 2 ≈ ptac 3 > acac 5 > thd 6 > btfac 4. Complexes 1 and 6 vapors demonstrated the lowest and the highest thermostability, respectively.

Crystal structure and thermal properties of (1,1,1,5,5,5-hexafluoropentanoato-4)··(dicarbonyl)iridium(I)

The Ir(CO)2(hfac) complex (hfac = CF3C(O)CHC(O)CF3) has been studied by X-ray crystallographic analysis. The crystallographic data are as follows: space group Cmc21, a = 8.680(4) Å, b = 18.951(1) Å, c = 6.491(3) Å, V = 1067.7(8) Å3, Z = 4, R = 0.0327. The structure is molecular; the coordination polyhedron of iridium adopts a distorted square geometry. The average Ir–O and Ir–C distances are 2.06(1) Å and 1.82(4) Å respectively. The OIrO and CIrC angles are nearly equal (88.7(5)° and 89(1)° respectively). The thermal properties of the complex have been studied by thermogravimetry.

Crystal structure and thermal properties of N,N′-(2,2-dimethylpropylene)-bis(acetylacetoneiminato)palladium(II)

Abstract[Pd(acacdmpda)] complex (1) is obtained for the first time by the interaction of [Pd(CH3CN)2Cl2], NaOH, and H2acacdmpda (acacdmpda = N,N′-(2,2-dimethylpropylene)-bis(acetylacetoneiminato-)) in acetonitrile. The compound is characterized by elemental analysis and IR spectroscopy; its structure is determined by single crystal X-ray diffraction. Complex 1 has a molecular structure. The coordination environment of the Pd2+ cation is a distorted square formed by O and N atoms of the tetradentately coordinated acacdmpda2– ligand. The average Pd–O and Pd–N bond lengths are 1.998(4) Å and 2.016(4) Å respectively. The N–Pd–O chelate angles are 92.34(10)° and 91.73(9)°; the N–Pd–N angle is 95.52(10)°. The thermal properties of 1 are studied by thermogravimetry. The complex passes quantitatively into the gas phase in the temperature range 225-325 °С.

CRYSTAL STRUCTURE OF TWO COMPLEXES CONTAINING tris-(β-DIKETONATO)MAGNATE ANION

Single crystal XRD is used to determine the structures of the complexes (H2TMEDA)[Mg(ptac)3]2 (1, TMEDA = Me2N(CH2)2NMe2, ptac = tBuCOCHCOCF3) and (H2TMEDA)[Mg(hfac)3](hfac) (2, hfac = CF3COCHCOCF3) at a temperature of 150 K. The crystallographic data for complex 1: a = 10.2919(3) Å, b = 10.9492(4) Å, c = 15.4159(6) Å, α = 87.117(1)°, β = 89.686(1)°, γ = 79,864(1)°, space group

Crystal Chemistry Study of Two Magnesium Complexes with Trifluoroacetylacetone

P\bar 1

Structure of two polymorphs of bis-trifluoroacetylacetonato-(N,N,N′N′-tetramethylethylenediamine)magnesium

Z = 1, R = 0.0573; for complex 2: a = 12.9446(2) Å, b = 23.0035(4) Å, c = 13.1473(3) Å, β = 98.779(1)°, space group P21/n, Z = 4, R = 0.0605. The structures are ionic; the metal atom coordinates six oxygen atoms of three β-diketonate ligands. The distances Mg-O in complex 1 are in the range 2.036(2)–2.0920(19) Å; the same distances in complex 2 are in the range 2.051(2)–2.076(2) Å. The spatial packing is determined by the system of hydrogen bonds between the (H2TMEDA)2+ cations and [Mg(ptac)3]−(1) or hfac−(2) anions. A thermogravimetric study of complex 1 is carried out.

Structure of Cu(II) and Pd(II) complexes with 2-(2,2-dimethylhydrazone)pentanone-4

Single crystal X-ray diffraction at a temperature of 150(2) K is used to determine the structures of two magnesium complexes with trifluoroacetylacetone: [Mg(tfac)2]3I and [Mg(H2O)2(tfac)2]·H2O II. Crystallographic data for I: space group P21/n, a = 12.5226(10) Å, b = 13.0591(7) Å, c = 12.6034(13) Å, β = 95.243(2)°, V = 2052.5(3) Å3, Z = 2; for II: space group P21/c, a = 10.826(2) Å, b = 7.0742(13) Å, c = 21.858(4) Å, β = 102.712(5)°, V = 1632.9(5) Å3, Z = 4. The isle structure of I is formed by linear trimeric molecules; in the structure of II the molecules of the complex and crystallization water form a layered framework using hydrogen bondings; the coordinated water molecules are in a trans position. The magnesium atoms have a distorted octahedral coordination environment, the Mg–O distances are 1.991(4)- 2.146(4) Å and 2.040(5)-2.073(5) Å in molecules of I and II respectively.

Structure and thermal properties of (1,1,1-trifluoro-4-methyliminopentanoato-2) (cyclooctadiene-1,5)iridium(I)

The structures of two polymorphs [Mg(tmeda)(tfac)2] (tmeda = N,N,N′N′-tetramethylethylenediamine, tfac = trifluoroacetylacetonate anion) are studied by single crystal XRD. The crystallographic data are as follows: for the α-modification, space group P21/c, a = 8.0874(4) Å, b = 20.2826(11) Å, c = 12.8759(7) Å, β = 90.6350(1)°, V = 2111.5(19) Å3, Z = 4, R = 0.0583; for the β-modification, space group C2/c, a = 8.8698(4) Å, b = 13.3441(8) Å, c = 18.1189(11) Å, β = 92.280(2)°, V = 2142.8(2) Å3, Z = 4, R = 0.0537. Both structures are composed of monomeric complex molecules; the magnesium coordination environment is a distorted octahedron; tfac ligands are in the trans-position. The interatomic distances and bond angles are identical in the molecules; the packing motif is the only distinction between the two polymorphs.

Crystal structure of (1,1,1-trifluoro-5,5-dimethylhexan-2,4-dionato)silver(I)

Palladium(II) and copper(II) complexes with 2-(2,2-dimethylhydrazone) pentanone-4 are synthesized for the first time. The compounds are characterized by IR and NMR spectroscopy, elemental and single crystal X-ray diffraction analyses. The palladium complex crystallizes in the space group I41/a; the copper complex crystallizes in the space group P1̅. Both compounds are molecular; the palladium chelate core has a distorted square geometry and that of copper has a distorted tetrahedral geometry. The average M–O and M–N bond lengths are respectively 1.9808(15) Å and 2.0427(17) Å for M = Pd, 1.915(8) Å and 1.97(1) Å for M = Cu. The chelate O–M–N angles are 88.32(7)-91.67(7)° for M = Pd, 93.37(4)-99.02(5)° for M = Cu.

Structure of bis-(1,1,1-trifluoro-2-(methylimino)pentanoato-4)copper(II). Thermal properties of N-methylsubstituted copper(II) β-iminoketonates

A mixed-ligand iridium(I) complex with the imino-derivative of asymmetric β-diketone [Ir(cod)(Meitfac)] (cod = C8H12, cyclooctadiene-1,5; Mei-tfac = CF3C(O)CHC(NMe)CH3, 1,1,1-trifluoro-4-methyliminopentanoato-2) is synthesized for the first time. The compound is obtained by the interaction of [Ir(cod)Cl]2 with sodium β-iminoketonate in diethyl ether in the inert atmosphere and is characterized by elemental analysis, IR and NMR spectroscopy. According to the single crystal X-ray diffraction analysis, the compound is a monomeric molecular complex. The coordination environment of iridium is a distorted square; the Ir–O and Ir–N bond lengths are 2.031(1) Å and 2.086(2) Å respectively; the average distance Ir–C′ = 1.994(8) Å (C′ is the center of the С=С bond of the cod ligand); the NIrO chelate angle is 91.30(6)°, and the C′IrC′ angle is 87.63°. The crystal packing contains dimers formed by weak F…H–C hydrogen interactions. The thermal properties of the complex are studied by thermogravimetry. The compound passes into the gas phase in the temperature range 150-260 °C (mass loss 93.5%) and is characterized by a lower volatility as compared with its β-diketonate analog [Ir(cod)(tfac)] (tfac = CF3C(O)CHC(O)CH3, 1,1,1-trifluoropentadionato-2,4).