Di-μ-olato dinuclear copper(II) compounds. The structure of bis-μ-O-[(4,6,6-trimethyl-9-(pyridin-2-yl)-3,7-diazanon-3-en-1-olato)copper(II)] perchlorate

2000 ◽  
Vol 53 (8) ◽  
pp. 673 ◽  
Author(s):  
Neil F. Curtis ◽  
Olga P. Gladkikh ◽  
Keith R. Morgan ◽  
Sarah L. Heath

Preparations are reported for blue-green[{Cu(pyen)(eto)}2](ClO4)2[pyen is 2-(2-aminoethyl)pyridine, eto– isdeprotonated 2-aminoethanol] and of green[{Cu(pyaceto)}2](ClO4)2,formed by reaction of this compound with acetone[pyaceto– is deprotonated4,6,6-trimethyl-9-(pyridin-2-yl)-3,7-diazanon-3-en-1-ol]. The structureof[{Cu(pyaceto)}2](ClO4)2shows a unit cell containing two independent, but closely similar,centrosymmetrical dinuclear diolato-bridged cations. The copper(II) ions arein square pyramidal coordination, with the two bridging oxygen atoms, and theimine and secondary amine nitrogen atoms in the basal plane, with the pyridinenitrogen atom more weakly coordinated axially. Mean dimensions for the twocations are Cu–Cu# 2.99, Cu–Nbasal 2.01,Cu–O 1.96, Cu–Naxial 2.24 Å,O–Cu–O# 99, Cu–O–Cu# 81, C–O–Cu110, C–O–Cu# 130˚[C30H46Cl2Cu2N6O10,monoclinic, space group P21/n, a 13.487(1),b 13.356(1), c 20.921(2) Å,β 103.235(3)˚, R1 = 0.0516 for 4694reflections]. Magnetic susceptibilities (100–300 K) showantiferromagnetic spin coupling for[{Cu(pyaceto)}2](ClO4)2and[{Cu(pyen)(eto)}2](ClO4)2with singlet–triplet level separation J of–110(10) and –65(10) cm–1,respectively, indicating that[{Cu(pyen)(eto)}2](ClO4)2also has a dinuclear structure.

1994 ◽  
Vol 47 (10) ◽  
pp. 1885 ◽  
Author(s):  
NF Curtis ◽  
AR Davis ◽  
FWB Einstein

Intermediate products have been isolated from the reaction of (4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dihydrazone )nickel(II) perchlorate with butane-2,3-dione which finally yields the macrocyclic product (3,4,7,9,9,14,14,16-octamethyl-1,2,5,6,10,13-hexaazacyclohexa-deca-2,4,6,16-tetraene)nickel(II) perchlorate , [Ni( omht )] (ClO4)2. An initial violet product is assigned a structure with the macrocyclic ligand 3-acetyl-3,6,8,8,13,13,15-heptamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15-diene. In water this converts into an equilibrium mixture of the tautomeric cations blue cis-aqua(3,4,7,9,9,14,14,16-octamethyl-1,2,5,6,10,13-hexaazacyclohexadeca-1(16),4,6-trien-3-ol)nickel(II), cis-[Ni(L2)(H2O)]2+, and orange (3,6,8,- 8,13,13-hexamethyl-4,5,9,12-tetraazahexadeca-3,5-diene-2,15-dione 15-hydrazone)nickel(II), [Ni(L3)]2+. The rates at 25°C of the forward and reverse reactions of this tautomerism, and of the slower conversion of the equilibrium mixture to [Ni( omht )](ClO4)2, are reported. The structure of cis -[Ni(L2)(H2O)](ClO4)2.3H2O has been determined by X-ray diffractometry (monoclinic, space group P21/n, a 9.694(8), b 19.218(14), c 16.652(9) Ǻ, β 94.88(1)°, R 0.079 for 3254 reflections). This has NiII in octahedral coordination by secondary amine nitrogen atoms 10 and 13, hydrazone nitrogen atoms 1 and 6, and the carbinolamine oxygen substituent at position 3 of the pentadentate macrocyclic ligand L2, with a water molecule coordinated cis to the hydroxy group. Compounds of the tautomeric cations [Ni(L2)]2+ and [Ni(L3)]2+ with coordinated thiocyanate, azide, nitrite, oxalate and acetate are described.


1999 ◽  
Vol 55 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Martina Walker ◽  
Ehmke Pohl ◽  
Regine Herbst-Irmer ◽  
Martin Gerlitz ◽  
Jürgen Rohr ◽  
...  

The crystal structures of Emycin E (1), di-o-bromobenzoyl-Emycin F (2) and o-bromobenzoyl-Emycin D (3) have been determined by X-ray analysis at low temperature. Emycin E and o-bromobenzoyl-Emycin D both crystallize with two molecules in a triclinic unit cell. These two structures can be solved and refined either in the centrosymmetric space group P\bar 1, with apparent disorder localized at or around the expected chiral centre, or in the non-centrosymmetric space group P1 as mixtures of two diastereomers without disorder. Only the latter interpretation is consistent with the chemical and spectroscopic evidence. Refinements in the centrosymmetric and non-centrosymmetric space groups are compared in this paper and are shown to favour the chemically correct interpretation, more decisively so in the case of the bromo derivative as a result of the anomalous dispersion of bromine. Structures (1) and (3) provide a dramatic warning of the dangers inherent in the conventional wisdom that if a structure can be refined satisfactorarily in both centrosymmetric and non-centrosymmetric space groups, the former should always be chosen. In these two cases, despite apparently acceptable intensity statistics and R factors (5.87 and 3.55%), the choice of the centrosymmetric space group leads to the serious chemical error that the triclinic unit cell contains a racemate rather than two chiral diastereomers! The weakest reflections are shown to be most sensitive to the correct choice of space group, underlining the importance of refining against all data rather than against intensities greater than a specified threshold. The use of similar-distance restraints is shown to be beneficial in both P1 refinements. Di-o-bromobenzoyl-Emycin F crystallizes in the monoclinic space group P21 with one molecule in the asymmetric unit and so does not give rise to these problems of interpretation. The absolute configuration of the two bromo derivatives, and hence the Emycins in general, was determined unambiguously as S at the chiral centre C3.


1996 ◽  
Vol 51 (2) ◽  
pp. 277-285
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut

Abstract The synthesis of salts of the type RnSH3-n+MF6- (R = C2H5, i-C3H7; n = 1, 2; M = As, Sb) by protonation of the corresponding thiols and sulfides in the superacid systems HF/MF5 is reported. The salts have been characterized by vibrational and NMR spectroscopic methods. Isopropylsulfonium hexafluoroantimonate is the first known example of a sulfonium salt, for which a SH bond distance has been determined by a crystal structure analysis, i-C3H7SH2+SbF6- crystallizes in the monoclinic space group P21/m with a = 568.0(4), b = 801.1(6), c = 1019.7(8) pm, β = 82.63(6) °, with two formula units per unit cell.


1996 ◽  
Vol 51 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut

Abstract CH3S(0)C1 reacts in HF as solvent with MF5 (M = As, Sb) to give products CH3S(Cl)OMF5 (M = As, Sb). The new compounds are stable below 253 K and were charac­ terized by Raman and NMR spectroscopy.In addition, the crystal structure of CH3S(Cl)OSbCl5 has been determinated. The complex crystallizes in the monoclinic space group P21/n with a = 644.3(5), b = 1905.9(14), c = 900.0(7) pm, β = 99.27(6)° with four formula units per unit cell.


1985 ◽  
Vol 40 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Kay Jansen ◽  
Kurt Dehnicke ◽  
Dieter Fenske

The syntheses and IR spectra of the complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, CI, Br and the counter ion PPh4⊕ are reported. The azido and the bromo complexes are obtained from a solution of [Mo2(O2CPh)4] with PPh4N3 in pyridine or by reaction with PPh4Br in CH2Br2, respectively. When (PPh4)2[Mo2(O2CPh)4(N3)2] is dissolved in CH2Cl2, nitrogen is evolved and the complex with X = CI is obtained. The crystal structure of (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 was determined from X-ray diffraction data (5676 observed independent reflexions, R = 0.042). It crystallizes in the monoclinic space group P21/n with four formula units per unit cell; the lattice constants are a = 1549, b = 1400, c = 1648 pm, β = 94.6°. The centrosymmetric [Mo2(O2CPh)4Cl2]2⊖ ion has a rather short Mo-Mo bond of 213 pm, whereas the MoCl bonds are very long (288 pm)


1995 ◽  
Vol 48 (12) ◽  
pp. 1933 ◽  
Author(s):  
CT Abrahams ◽  
GB Deacon ◽  
CM Forsyth ◽  
WC Patalinghug ◽  
BW Skelton ◽  
...  

With the facile displacement being utilized of thf from Yb(pin)2(thf)4 (pin = 2-phenylindol-1-yl, thf = tetrahydrofuran) in toluene solution, the complexes Yb(pin)2(dme)2 (dme = 1,2- dimethoxyethane), Yb(pin)2 (tmen)(tmen = N,N,N′,N′-tetramethylethane-1,2-diamine) and Yb(pin)2(diglyme)(thf) (diglyme = bis(2-methoxyethyl) ether) have been prepared from the respective ligands and Yb(pin)2(thf)4. Yb(pin)2 (diglyme) (thf) [monoclinic, space group P 21 /c, a 15.35(1), b 16.179(5), c 14.45(2) Ǻ, β 107.51(8)°, Z 4, R 0.044 for 2956 (I > 3σ(I)) 'observed' reflections] has a monomeric six-coordinate structure with transoid nitrogen donor atoms, N-Yb-N 143.6(4)° and an irregular coordination polyhedron described as either a distorted trigonal prism or a monocapped square pyramid. Attempted crystallization of Yb(pin)2 (thf) by partial desolvation of Yb(pin)2(thf)4 in hot toluene, containing a trace of dme, gave a mixture of red Yb(pin)2(thf) and orange [Yb(pin)2(dme)]2. The latter was independently synthesized by partial desolvation of Yb(pin)2(dme)2 in toluene. An X-ray crystal structure showed [Yb(pin)2(dme)]2 [monoclinic, space group P 21/c, a 11 .614(2), b 15.945(7), c 15.327(4) Ǻ, β 110.19(2)°, Z 2 dimers, R 0.070 for 2314 (I ≥ 3σ(I)) 'observed' reflections] to be a dimer with two bridging pin ligands, coordinated through nitrogen only. There is an approximately square pyramidal five-coordinate ytterbium environment with an apical dme oxygen, and with two bridging nitrogens, a terminal nitrogen, and a dme oxygen in the basal plane.


1990 ◽  
Vol 45 (8) ◽  
pp. 1167-1176 ◽  
Author(s):  
Alfons Möhlenkamp ◽  
Rainer Mattes

The reaction of NaReO4 with thiobenzoylhydrazine yields Re(NHNC(S)Ph)3- DMF (1). With ReOCl3(PPh3)2 thiobenzoylhydrazine reacts to give Re(NHNC(S)Ph)3 · OPPh3 (2) and in the presence of HCl to yield [Re(NHNC(S)Ph)(NHNHC(S)Ph),]Cl · 1/3 C2H5OH -1 /3 H2O (3). The structures of 1-3 have been determined. 1: monoclinic, space group P2,/c, a = 1150.1(9), b = 2050.0(9), c = 1181.0(8) pm, β = 109.62(5)°, Z = 4, 2980 reflections, R = 0.055; 2: trigonal, space group R 3, a = 1399.8(1), c = 1684.0(1) pm, Z = 3, 1419 reflections, R = 0.033; 3: monoclinic, space group P2,/c, a = 1446.8(3), b = 3220.7(5), c = 1727.1(4) pm, β = 108.42(2)°, Z = 12, 6112 reflections, R = 0.062. In 1 and 2 three N,S-chelating ligands NHNR (R = C(S)Ph) are coordinated to the central rhenium atom. The ligand structure is intermediate between a diazene and a hydrazido(2–) structure. In 3 each rhenium atom is coordinated by one NHNR and two NHNHR ligands, all N,S-chelating. The latter can be considered as protonated diazene ligands. The unit cell contains three isomeric coordination polyhedra.


1995 ◽  
Vol 50 (4) ◽  
pp. 699-701 ◽  
Author(s):  
Norbert W. Mitzel ◽  
Jürgen Riede ◽  
Klaus Angermaier ◽  
Hubert Schmidbaur

The solid-state structure of N,N-dibenzylhydroxylamine (1) has been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 21/n with four formula units in the unit cell. N,N-dibenzylhydroxylamine dimerizes to give N2O2H2 sixmembered rings as a result of the formation of two hydrogen bonds O - H ··· N in the solid state.


1991 ◽  
Vol 46 (6) ◽  
pp. 789-794 ◽  
Author(s):  
M. Somer ◽  
D. Thiery ◽  
K. Peters ◽  
L. Walz ◽  
M. Hartweg ◽  
...  

The compounds Cs6M2X4 (M = Al, Ga; X = P, As) were synthesized from stoichiometric mixtures of Cs, M and Cs4X6 in sealed Nb ampoules at 950 K. They are isotypic and crystallize in the monoclinic space group P21/c (No. 14) with Z = 4 formula units per unit cell. The anion partial structure is characterized by isolated [M2X4]6- units with relatively short distances for the terminal d(M–X) bonds corresponding to a Pauling Bond Order PBO = 1.5. The distances d(M–X) of the four-membered M2X2 rings correspond to single bonds.The FIR spectra have been interpreted on the basis of the [M2X4]6- units with 2/m 2/m 2/m-D2h, symmetry by considering a factor group splitting. The assignment of the observed frequencies is supported by a normal coordinate analysis.


1989 ◽  
Vol 44 (7) ◽  
pp. 778-785 ◽  
Author(s):  
Edmund Hartmann ◽  
Raimund Schmid ◽  
Joachim Strähle

[Ag(MeOC6H4N3C6H4OMe)]2 (1) is formed in THF from AgNO3 , and the triazenide anion, as obtained from the corresponding triazene and Na. 1 crystallizes from pyridine in the form of orange-yellow , air stable crystals with the com position 1·2/3 C5H5N: space group P 1̅ with a = 1468.0(5), b = 1514.1(6), c - 1316.1(3) pm, a = 113.45(3)°, β = 1 1 4 .8 1 (2 )°, γ = 66.78(3)°, Z - 3. The triazenide ion functions as a bridging ligand forming planar (AgN3)2 heterocycles. The unit cell contains two symmetry-independent dinuclear complexes, one of which is centrosymmetrical. The short Ag -Ag distances of 268.0 and 269.8 pm suggest Ag -Ag bonding. The pentaazadienido complexes Ag(RN5R) with R = p -MeO - C6H4 (2), p -EtO - C6H4 (3), p-Cl -C6H4 (4), p -F -C6H4 (5), are obtained from saturated solutions of the pentaazadiene in conc. NH3 and AgNO3 , as explosive, red precipitates which are stable in air. Crystals of 2 and 3 · C5H5N are obtained from pyridine. 2 crystallizes in the monoclinic space group P21/c: a - 583.7(6), b = 1705.1(9), c = 1489.6(9) pm. β = 96.2(1)°, Z = 2; 3 · C5H5N is triclinic (space group P 1̅) with a = 1160.4(4). b = 1671.0(6), c = 509.0(1) pm. a = 97.51(2)°, β = 97.36(2)°, γ = 81.51(3)°, Z = 1. The complexes 2 and 3 are dinuclear with the pentaazadienide ion as a (N1)-η1,(N5)-η1 bridging ligand in 2 and a (N1)-η1, (N3)-η1 bridging ligand in 3. The bridging mode in 3 results in a short Ag -Ag contact of 283.44 pm. The Ag -N distances range from 210.8 to 215.7 pm in 1 and from 215.0 to 220 pm in (2) and (3).


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