scholarly journals Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

2016 ◽  
Vol 12 ◽  
pp. 2478-2489 ◽  
Author(s):  
Constantin Mamat ◽  
Marc Pretze ◽  
Matthew Gott ◽  
Martin Köckerling
Keyword(s):  
Click Reaction ◽  
Building Blocks ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Acetate Solution ◽  
Staudinger Ligation ◽  
Space Group ◽  
H Nmr ◽  
Piperazine Derivatives ◽  
Nmr Characterization

Novel, functionalized piperazine derivatives were successfully synthesized and fully characterized by 1H/13C/19F NMR, MS, elemental analysis and lipophilicity. All piperazine compounds occur as conformers resulting from the partial amide double bond. Furthermore, a second conformational shape was observed for all nitro derivatives due to the limited change of the piperazine chair conformation. Therefore, two coalescence points were determined and their resulting activation energy barriers were calculated using 1H NMR. To support this result, single crystals of 1-(4-nitrobenzoyl)piperazine (3a, monoclinic, space group C2/c, a = 24.587(2), b = 7.0726(6), c = 14.171(1) Å, β = 119.257(8)°, V = 2149.9(4) Å3, Z = 4, D obs = 1.454 g/cm3) and the alkyne derivative 4-(but-3-yn-1-yl)-1-(4-fluorobenzoyl)piperazine (4b, monoclinic, space group P21/n, a = 10.5982(2), b = 8.4705(1), c = 14.8929(3) Å, β = 97.430(1)°, V = 1325.74(4) Å3, Z = 4, D obs = 1.304 g/cm3) were obtained from a saturated ethyl acetate solution. The rotational conformation of these compounds was also verified by XRD. As proof of concept for future labeling purposes, both nitropiperazines were reacted with [18F]F–. To test the applicability of these compounds as possible 18F-building blocks, two biomolecules were modified and chosen for conjugation either using the Huisgen-click reaction or the traceless Staudinger ligation.

Supramoleküle aus Kronenethern und geminalen Sulfonen: Synthese von vier binären Komplexen und Kristallstruktur von (CH2CH2O)4·2H 2C(SO2C2H5)2/Supramolecules of Crown Ethers with Geminal Sulfones: Synthesis of Four Binary Complexes and Crystal Structure of (CH2CH2O )4·2H2C(SO2C2H5)2

1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Binary Complexes ◽  
Cyclic Polyethers ◽  
Adjacent Unit ◽  
Methylene Group

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.

The Dichloroplatinum(II) and Dichloropalladium(II) Complexes of 1,4-Diazacycloheptane: Preparative, Structural and Conformational Studies

1996 ◽  
Vol 49 (12) ◽  
pp. 1301 ◽  
Author(s):  
GW Allen ◽  
ECH Ling ◽  
LV Krippner ◽  
TW Hambley
Keyword(s):  
Crystal Structures ◽  
Chelate Ring ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Membered Chelate Ring ◽  
Alternative Conformation

The preparation and purification of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] ( hpip = homopiperazine = 1,4-diazacycloheptane) are described. Crystal structures of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] have been determined by X-ray diffraction methods and refined to R values of 0.023 (932 F) and 0.023 (948 F). The crystals of [Pt( hpip )Cl2] are orthorhombic, space group Pbcm , a 7.7019(8), b 9.8080(12), c 12.1944(14) Ǻ, and those of [Pd( hpip )Cl2] are monoclinic, space group P21/m, a 6.1001(9), b 11.527(2), c 6.458(I) Ǻ, β 106.30(2)°. The seven- membered rings of the ligands in both complexes adopt boat-like conformations in which the five- membered chelate ring has an eclipsed N-C-C-N group and the six- membered chelate ring adopts a chair conformation. Molecular mechanics methods were used to investigate whether this conformation was a crystallographic artefact but it was found to be real. An alternative conformation in which the six-membered chelate ring adopts a skew-boat conformation was also investigated. It was found to be less stable than the conformation observed in the crystal structures, but to a degree that depends on whether non-bonded interactions involving the metal atom were included or not.

scholarly journals Chemie polyfunktioneller Moleküle, 114 [1]. Synthese und Struktur eines ionischen und nichtionischen, cyclischen Carbaphosphazens und eines Cobalt(III)phosphazen-Komplexes / Chemistry of Polyfunctional Molecules, 114 [1]. Synthesis and Structure of an Ionic and Non Ionic Cyclic Carbaphosphazene and of a Cobalt(III)phosphazene Complex

1994 ◽  
Vol 49 (12) ◽  
pp. 1763-1773 ◽  
Author(s):  
Jochen Ellermann ◽  
Jörg Sutter ◽  
Falk A. Knoch ◽  
Matthias Moll ◽  
Walter Bauer
Keyword(s):  
Mass Spectra ◽  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
H Nmr

Reaction of (1) in CH2Cl2 with benzimidazole yields . The salt [4]+BPh4- has been prepared in THF by metathesis of [4]+Cl- with NaBPh4. Deprotonation of the cationic ring in [4]+BPh4- was accomplished using 1,8-diazabicyclo[5.4.01,7]undec-7-ene and resulted in the six-membered carbacyclophosphazene (6). Treating 1 with 8 -hydroxyquinoline in CH2Cl2 yields the octahedral cis-complex = 8-oxyquinolinate group). The com pounds [4]+BPh4-, 6 and 7 are characterized by their IR, Raman, 31P{1H} NMR, 13C{1H} NMR, 1H NMR and mass spectra. Crystals suitable for X-ray structure analyses have been obtained for [4]+BPh4- and 7×0.5 CH2Cl2. The colourless plates of [4]+BPh4- crystallize in the triclinic space group P1̄, with the lattice constants a = 1172.7(3), b = 1326.2(3), c = 1806.1(6) pm; α = 100.79(2), β = 103.71(3), γ = 108.18(2)°. The black blocks of 7×0.5 CH2Cl2 crystallize in the monoclinic space group P 21/c with the lattice constants a = 1159.0(10), b = 2008.9(10), c = 2034.6(12) pm; β = 105.86(5)°.

Polysulfonylamine, XCVII [1] Di(organosulfonyl)amine und ihre konjugierten Anionen als simultane Baugruppen in zwei supramolekularen Strukturen / Polysulfonylamines, XCVII [1] Di(organosulfonyl)amines and their Conjugate Anions as Simultaneous Building Blocks in Two Supramolecular Structures

1997 ◽  
Vol 52 (10) ◽  
pp. 1229-1236 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Packing ◽  
Building Blocks ◽  
Complex Compounds ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
Diffraction Structure ◽  
Bond System ◽  
Bond Network ◽  
Anion Interaction

The complex compounds 4HN (SO2Me)2 · (diaza-18-crown-6) (1) and Na[N(SO2Ph)2] · 2HN(SO2Ph)2 · 2 (12-crown-4) · 2 MeOH (2) were obtained from their components and characterized by low-temperature X-ray diffraction. Structure 1 (monoclinic, space group P21/n) displays centrosymmetric formula units consisting of a biangular diazonia-18-crown-6 dication, two (MeSO2)2N− anions situated above and below the macrocycle and linked to the NH2+ groups via an N - H ··· O and N -H ··· N bond system, and finally two HN(SO2Me)2 molecules, each forming an N -H ··· O bond to one of the anions. The molecule-anion entity represents an iso form of the [(RSO2)2N -H ··· N (SO2R)2]− homoconjugates previously described. The crystal packing of 1 is stabilized by an extensive and highly organized [H2C -H ··· O(S)] hydrogen bond network. Structure 2 (monoclinic, space group P21/n) exhibits inconspicuous [Na(12-crown-4)2]+ cations and, as a striking feature, supramolecular anions assembled from a central (PhSO2)2N− ion, two MeOH molecules flanking the amide anion, and two HN (SO2Ph)2 molecules bonded to the MeOH moieties. The assembly is held together by two N -H ··· O(H )(Me) bonds, one MeO -H ··· N− bond and one MeO -H ··· O(anion) interaction. For both structures, conformational peculiarities of the N(SO2C)2 groups are discussed.

Structure and conformation of the N-β-propionic acids of cyclohexan[b]indole and cyclooctan[b]indole

1986 ◽  
Vol 64 (9) ◽  
pp. 1829-1835 ◽  
Author(s):  
Carmen Esteban-Calderon ◽  
Martín Martinez-Ripoll ◽  
Severino García-Blanco ◽  
Fernando Temprano ◽  
José Gonzalo Rodriguez
Keyword(s):  
Propionic Acid ◽  
Monoclinic Space Group ◽  
Trans Conformation ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
H Nmr ◽  
Ray Methods

The structures of cyclohexan[b]indole N-β-propionic acid (1) and cyclooctan[b]indole N-β-propionic acid (2) have been determined by X-ray methods. The conformational populations of their N-β-propionic chains have been determined in solution by 1H nmr analyses. Crystals of 1 are triclinic, space group [Formula: see text] with a = 12.3562(4), b = 11.0727(3), c = 10.2050(4) Å, α = 108.519(3), β = 83.941(3), γ = 104.826(3)°, and Z = 4. Crystals of 2 are monoclinic, space group P21/c, with a = 5.636(1), b = 18.937(3), c = 13.976(4) Å, β = 98.84(3)°, and Z = 4. In both structures, the molecules are linked forming dimers through centrosymmetric H bonds. In solution the trans conformation of the chain is the preferred one in both compounds and increases with dilution until a constant value is reached.

One-dimensionally Hydrogen-bonded Silver(I) Saccharinate Complexes with N-(2-Aminoethyl)piperidine and N-(2-Hydroxyethyl)piperidine: Synthesis, Crystal Structures, FTIR and Thermal Studies

2008 ◽  
Vol 63 (2) ◽  
pp. 139-142 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
Orhan Büyükgüngör
Keyword(s):  
Thermal Studies ◽  
Chair Conformation ◽  
Metallic Silver ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
One Dimensional ◽  
X Ray ◽  
The Individual

Two new complexes [Ag(sac)(aepip)] (1) and [Ag(sac)(hepip)] (2) have been obtained by the reaction of AgNO3 with Na(sac)・2H2O (sac = saccharinate) in the presence of N-(2-aminoethyl)piperidine (aepip) and N-(2-hydroxyethyl)piperidine (hepip), and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group C2 and triclinic space group P1, respectively. In both complexes, silver( I) is tricoordinated. The sac ligand is N-coordinated, while aepip and hepip behave as N-N and N-O bidentate chelating ligands, respectively. The pip rings of both aepip amd hepip ligands adopt typical ‘chair’ conformation. The individual molecules are linked into one-dimensional chains by two N-H···O hydrogen bonds in 1, and one O-H···O hydrogen bond in 2. TG-DTG curves illustrated that the endothermic elimination of aepip and hepip ligands takes place in the early stages of thermal decomposition, while that of the sac moiety occurs exothermically at higher temperatures to give metallic silver

Conformation of azaphosphorinane ring. Crystal structures of 2,2,6,6-tetramethyl-4,4-diphenyl-1,4-azaphosphorinanium perchlorate and 2,2,6,6-tetramethyl-4-oxo-4-phenyl-1,4-azaphosphorinan-1-oxyl (stable nitroxy radical)

1983 ◽  
Vol 61 (3) ◽  
pp. 427-433 ◽  
Author(s):  
Miroslaw Cygler ◽  
Janusz Skolimowski
Keyword(s):  
Crystal Structures ◽  
Heavy Atom ◽  
Phenyl Group ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Compound I ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Unit Cell Dimensions

Crystal structures of 2,2,6,6-tetramethyl-4,4-diphenyl-1,4-azaphosphorinanium perchlorate (I) and 2,2,6,6-tetramethyl-4-oxo-4-phenyl-1,4-azaphosphorinan-1-oxyl (II) were determined. Compound I crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 18.2967(7), b = 10.9413(6), c = 20.8714(13) Å, β = 90.79(1)° (at 115 K), and II crystallizes in the orthorhombic space group Pn21a with a = 8.076(1), b = 10.139(1), c = 17.894(1) Å. Intensity data were measured on a diffractometer at 115 K for I and at the room temperature for II. The structures were solved by a combination of heavy-atom and direct methods and refined to R = 0.036 (3968 reflections) for I and 0.039 (1451 reflections) for II.The azaphosphorinane ring adopts a chair conformation in both molecules, being flattened in the P part in I and in the N part in II. In molecule I the equatorial phenyl group is nearly parallel to the approximate plane of symmetry of the molecule, and the axial phenyl group is perpendicular to that plane. In molecule II the P=O bond is axial and the phenyl group is equatorial. The CN(O)C group is not planar. The N—O bond makes an angle of 18.0(3)° with the CNC plane. The CNC angle of 129.3(3)° is larger than that found in nitroxypiperidine analogues.

Ruthenium(II) complexes of the thiacyclophane ligands 2,5,8-trithia[9]-o-cyclophane (TT[9]OC) and 5-oxa-2,8-dithia[9]-o-cyclophane (ODT[9]OC). Structures of RuCl2(DMSO)(TT[9]OC) and RuCl2(PPh3)(ODT[9]OC)

1995 ◽  
Vol 73 (7) ◽  
pp. 1102-1110 ◽  
Author(s):  
Broer de Groot ◽  
Hilary A. Jenkins ◽  
Stephen J. Loeb ◽  
Shannon L. Murphy
Keyword(s):  
Coordination Mode ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Ruthenium Hydride ◽  
H Nmr ◽  
Coordination Sites ◽  
Ligand Displacement ◽  
Displacement Reactions

Ruthenium(II) complexes of the thiacyclophane ligands 2,5,8-trithia[9]-o-cyclophane (TT[9]OC) and 5-oxa-2,8-dithia[9]-o-cyclophane (ODT[9]OC) were synthesized by ligand displacement reactions employing RuCl2(DMSO)4, RuCl2(PPh3)3, and RuHCl(PPh3)3 as starting materials. X-ray crystal structures of two of these complexes, RuCl2(DMSO)(TT[9]OC) and RuCl2(PPh3)(ODT[9]OC), demonstrate how TT[9]OC and ODT[9]OC bind to Ru(II). RuCl2(DMSO)(TT[9]OC) crystallized as the DMSO solvate in the orthorhombic space group Pbca with a = 19.590(5), b = 16.849(4), c = 13.149(4) Å, V = 4340(3) Å3, and Z = 8. The structure refined to R = 5.27% and Rw = 6.27% for 2472 reflections with Fo2 > 3σ(Fo2). RuCl2(PPh3)(ODT[9]OC) crystallized as a ClCH2CH2Cl solvate in the monoclinic space group P21/c with a = 7.912(1), b = 22.419(5), c = 18.794(3) Å, β = 101.12(1),° V = 3271.2(9) Å3, and Z = 4. The structure refined to R = 4.96% and Rw = 5.14% for 1800 reflections with Fo2 > 3σ(Fo2). Both compounds are octahedral with the thiacyclophane ligand bound through three donor atoms in a facial coordination mode, cis chlorine atoms, and the unique ancillary ligand, DMSO or PPh3, bound trans to the central S or O donor of the macrocycle. The X-ray structures support 1H NMR spectral evidence which shows that the ligands are bound in an "endo" mode for L = DMSO and in an "exo" mode when L = PPh3. The reaction of RuHCl(PPh3)3 with TT[9]OC yields the ruthenium hydride complex RuHCl(PPh3)2(TT[9]OC). 1H and 31P NMR spectroscopy are consistent with an octahedral species for which the macrocycle occupies only two coordination sites acting as a bidentate η2-chelating ligand. Keywords: thioether, macrocycle, hydride, crystal structure.

Lewis acidic titanium species: the synthesis, structure, bonding and molecular modelling considerations of the complexes Ti(NR2)3Cl (R = Me, Et)

1991 ◽  
Vol 69 (2) ◽  
pp. 357-362 ◽  
Author(s):  
David G. Dick ◽  
Roger Rousseau ◽  
Douglas W. Stephan
Keyword(s):  
Molecular Modelling ◽  
Energy Minimization ◽  
Variable Temperature ◽  
Structural Data ◽  
Steric Effects ◽  
Monoclinic Space Group ◽  
Nmr Studies ◽  
Space Group ◽  
H Nmr ◽  
Multiple Bonding

Reaction of simple amides with TiCl4 affords mixed amido-chloride species Ti(NR2)4−nCln. The trisamide-chloride species Ti(NR2)3Cl can be prepared directly employing three equivalents of amide or by reaction Ti(NR2)4 with TiCl4. The compound Ti(NMe2)3Cl, 1, crystallizes in the trigonal space group [Formula: see text] with a = 11.525(5), c = 14.939(3) Å, Z = 6, and V = 1718(1) Å3. The compound Ti(NEt2)3Cl, 2, crystallizes in the monoclinic space group P21/c, with a = 8.385(2) Å, b = 15.958(2) Å, c = 14.230(4) Å, β = 107.79(1)°, Z = 4, and V = 1813(1) Å3. The geometry of the Ti coordination sphere in these complexes is best described as pseudo-tetrahedral. The structural data are consistent with Ti—N multiple bonding. Preliminary results of EHMO calculations are consistent with dπ—pπ Ti—N bonding. Attempts to replace the halides with phosphides (LiPR2, R = Me, Et, Ph) led not to the Ti(IV) phosphido species, but rather to redox chemistry yielding Ti(III) amides and P2R4. The barrier to rotation about the Ti—N bonds has been considered. Variable temperature 1H NMR studies reveal that the barrier is small. Extended Hückel total energy minimization calculations have been performed. In addition, MMX calculations of the barrier to Ti—N rotation are reported. The results of these calculations imply that the rotational barrier is dominated by steric effects. Key words: titanium amides, structures, Ti—N bonding

Aluminium-Germanide der zweiwertigen Lanthanoide Eu und Yb: Synthese, Strukturchemie und chemische Bindung

2011 ◽  
Vol 66 (8) ◽  
pp. 793-812
Author(s):  
Britta Bauer ◽  
Caroline Röhr
Keyword(s):  
Alkaline Earth ◽  
Building Blocks ◽  
Structure Type ◽  
Monoclinic Space Group ◽  
Total Density ◽  
Structural Element ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Type Orthorhombic ◽  
Total Density Of States

In the course of attempts to substitute Ca by Yb and Sr by Eu in known alkaline earth Al-germanides, the four new ternary compounds Eu3Al1.8Ge2.2, Eu3 Al2Ge4, Yb2 AlGe3, and Yb17Al8Ge19 have been synthesized from mixtures of the elements and their crystal structures determined by means of single-crystal X-ray data. The two europium compounds Eu3Al1.8Ge2.2 (Ta3B4 structure type, orthorhombic, space group Immm, a = 417.68(3), b = 470.70(3), c = 1897.2(2) pm, Z = 2, R1 = 0.0439) and Eu3Al2Ge4 (Sr3Al2Ge4 structure type, monoclinic, space group C2/m, a = 1235.9(6), b = 416.8(2), c = 878.4(4) pm, β = 110.615(13)°, Z = 2, R1 = 0.0978) are isotypic with the corresponding strontium phases. After ionic decomposition, the layers [Al2- Ge4- ]6− in Eu3Al2Ge4 with four-bonded Al and three-bonded Ge atoms can be interpreted as electron-precise Zintl anions. In contrast, the planar ribbons 1∞[Al2/2Ge2Al2/2] of condensed six-membered rings in Eu3Al1.8Ge2.2 exhibit considerably shorter Al-Ge bonds and an Al-Al bond length of only 251 pm. Yb2AlGe3 (orthorhombic, space group Pnma, a = 682.20(10), b = 417.87(9), c = 1813.9(3) pm, Z = 4, R1 = 0.0415) crystallizes with the Y2AlGe3 structure type. Folded [Al2Ge2] ladders, also found in Eu3Al2Ge4 and the known compound Yb7Al5Ge8, are connected by planar cis/trans chains of Ge atoms. The total density of states calculated within the FP-LAPW|DFT band structure approach shows a distinct minimum at the Fermi level for the electron precise Zintl compound Eu3Al2Ge4, whereas π-bonding contributions are evident from the band structures of Eu3Al2Ge2 and Yb2AlGe3. In full accordance, the tDOS of both compounds exhibits no minimum at EF, small phase widths are possible for Eu3Al2Ge2 and related alkaline earth compounds, and Yb2AlGe3 is isotypic with several other more electron-rich LnIII compounds. The complicated structure of the new compound Yb17Al8Ge19 (tetragonal, space group P4/nmm, a = 1542.50(2), c = 788.285(8) pm, Z = 2, R1 = 0.0282) contains three different building blocks: distorted [Al4Ge4] heterocubane units are interconnected by four-bonded Ge atoms to form columns running along the c axis. Secondly, eight-membered rings are formed by alternating Al and Ge atoms, each being in a trigonal-planar Al/Ge coordination. The rings are terminated by Ge atoms (bonded to Ge of the ring) and linked to the first structural unit by a further Ge atom (bonded to Al of the ring). Thirdly, inside the large channels, which are formed by the packing of the eightmembered rings, Ge2 dumbbells are interspersed as a third structural element.

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