Synthese und Struktur von N,N,N‴,N‴‐Tetraisobutyl‐N′,N″‐isophthaloylbis(thioharnstoff) und Dimethanol‐bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato))dicobalt(II)

Synthesis and Structure of N,N,N?,N?‐Tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and Dimethanol‐bis(N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato))dicobalt(II) The synthesis and the crystal structure of the ligand N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and its Co^II‐complex are reported. The ligand co‐ordinates quadridentately forming a di‐bischelate. The donor atoms O and S are arranged in cis‐position around the central Co^II ions. In addition the co‐ordination geometry is determined by methanol molecules resulting in the co‐ordination number five. The complex crystallizes in the space group P1 (Z = 1) with two additional methanol molecules per formula unit. The free ligand crystallizes in the space group P1 (Z = 2) with one methanol molecule per formula unit. It shows the typical keto form of N‐acylthioureas with a protonated central N atom. The structures of both acylthiourea fragments come close to E,Z′‐configurations.     

Kristall- und Molekülstruktr von N,N′, N″- Trimethyl-N″- methylcarbamoylguanidiniumchlorid

N, N′, N″- Trimethyl-N″-Methyl-Carbamoylguanidinium Chloride The title compound is formed in small amounts by the chlorination of N, N′-dimethylurea with phosgene as a consecutive product, which crystallizes in the triclinic space group P1 with two formula units per cell. The cross-linkage of these two molecules with relative short N? H…?Cl…?H? N- bridges forming large, 16- membered ring systems is remarkable. The structure was refined to an R-value of 0.03.     

Synthese und Kristallstruktur von N,N,N′,N″,N″-Pentamethyl-diethylen-triamin-cokoordiniertem Natrium-bis(diphenylphosphanyl)amid und über ein [12]-Krone-4-Derivat

Chemistry of Polyfunctional Molecules. 128 [1]. Synthesis and Crystal Structure of N,N,N′,N″,N″-Pentamethyl-diethylene-triamine Cocoordinated Sodium Bis(diphenylphosphanyl)amide and about a [12]-Crown-4-Ether Derivative The metalation of bis(diphenylphosphanyl)amine [HN(PPh₂)₂ ( 4 )] with NaH in the presence of N,N,N′,N″,N″-pentamethyl-diethylene-triamine [PMDTA ( 2 )] at 105 °C in toluene affords the monomeric yellow sodium complex [(Ph₂P)₂NNa · PMDTA] ( 5 ). X-ray analysis reveals that the coordination sphere of the sodium ion consists of the chelating triamine ligand 2 and [N(PPh₂)₂]^– as N- and monodentate P-donor. Additional weak η¹ C-contacts to 2 and [N(PPh₂)₂]^– are discussed. In the presence of [12]-crown-4-ether, HN(PPh₂)₂ and NaH react to the dimeric yellow-green complex [{(Ph₂P)₂NNa}₂{[12]-crown-4}₅] ( 6 ). The compound 6 crystallizes in thin needles, but they are not suitable for X-ray analysis. The dimeric non ionic structure of 6 has been confirmed by mass spectroscopy and conductivity measurements.     

Synthese,Struktur und einige Reaktionen [N-(N′,N′,N″,N″-tetramethyl)-guanidinyl]-substituierter Phosphorylverbindungen

Synthesis, Structure, and some Reactions of N-(N′,N′,N″,N″-tetramethyl)guanidinyl-substituted Phosphoryl Compounds The tetramethylguanidinyl-substituted phosphoryl compounds 1 – 10 were prepared in the reaction of the appropriate chlorophosphoryl compounds with either N′,N′,N″,N″-tetramethylguanidine (HTMG) or N-trimethylsilyl-(N′,N′,N″,N″-tetramethyl)guanidine (TMSTMG). With methyl iodide 1 reacted with N-alkylation to give the ammonium salt 11. 1 reacted with BF₃ · Et₂O at both imino nitrogen atoms with formation of the bis-BF₃-adduct 12 . The X-ray structure determination of phenylphosphonic acid-bis(N′,N′,N″,N″-tetramethylguanidinide) 3 shows shortened PN-bonds and widened PNC-angles, consistent with the partial double bond character of the PN-bond.     

N,N,N′,N′,N″‐penta(methyl acrylate)diethylenetriamine: A novel ligand for atom transfer radical polymerization of methyl methacrylate

A novel ligand, N,N,N′,N′,N″‐penta (methyl acrylate) diethylenetriamine (MA₅‐DETA), was synthesized by the reaction of diethylenetriamine with methyl acrylate in almost quantitive yield. The polymerizations of methyl methacrylate with MA₅‐DETA as the ligand and α,α‐dichlorotoluene (DCT) and ethyl 2‐bromoisobutyrate (2‐EBiB) as the initiators, respectively, under different conditions were examined. The polymerization with CuCl/MA₅‐DETA/DCT was closely controlled in bulk and gave polymers with quite narrow molecular weight distributions (M_w/M_n's) of 1.16–1.29. The polymerization with the system CuBr/MA₅‐DETA/EBiB in bulk gave high activity. However, the system was not well controlled and gave the polymers with M_w/M_n = 1.35–1.53. The solution polymerization in anisole with CuBr/MA₅‐DETA/EBiB showed a better‐controlled nature. Moreover, the addition of CuBr₂ into the aforementioned system can further improve its controllability. The M_w/M_n's of the resulting polymers ranged from 1.11 to 1.21. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1963–1969, 2004     

Partial Synthesis of 3′-Hydroxy-2′-deoxy-2″,3″,4″,5″-tetrahydroverrucarin A. Verrucarins and roridins, 38th Communication [1]

The macrocyclic trichothecene triester 3′-hydroxy-2′-deoxy-2",3",4",5"-tetrahydroverrucarin A ( 37 ), has been synthesized starting from the sesquiterpene alcohol verrucarol ( 3 ), adipic acid and a derivative of mevalonic acid ( 14 ). The latter has been prepared from 4-(tetrahydro-2-pyranyloxy)-2-butanone ( 9 ).     

Synthese,Strukturen, NMR‐ und EPR‐Untersuchungen der binuklearen Bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenoureato))‐Komplexe des NiII und CuII

Synthesis, Structures, NMR and EPR Investigations of Binuclear Bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenoureato)) Complexes of Ni^II and Cu^II The synthesis of binuclear Cu^II and Ni^II complexes of the quadridentate ligand N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenourea) and their crystal structures are reported. The complexes crystallize monoclinic, P2₁/c (Z = 2). In the EPR spectra of the binuclear Cu^II complex exchange‐coupled Cu^II‐Cu^II pairs were observed. In addition the signals of a mononuclear Cu^II species are observed what will be explained with the assumption of an equilibrium between the binuclear Cu^II‐complex (Cu^II‐Cu^II pairs) and oligomeric complexes with “isolated” Cu^II ions. Detailed ¹³C and ⁷⁷Se NMR investigations on the ligand and the Ni^II complex allow an exact assignment of all signals of the heteroatoms.     

N,N,N′,N′,N″‐Pentamethyl‐N″‐[(trifluorosilyl)methyl] phosphoric triamide. First example of the existence of intramolecular PO→Si coordination bond in the Si‐containing phosphoric triamides

The N,N,N′,N′,N″‐pentamethyl‐N″‐(trifluorosilylmethyl)phosphoric triamide O?P(NMe₂)₂N(Me) CH₂SiF₃ with intramolecular P?O→Si coordination was formed by the reaction of N,N,N′,N′,N″‐pentamethyl‐N″[(triethoxysilyl)methyl]phosphoric triamide with BF₃·Et₂O. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthese,Struktur und EPR‐Untersuchungen von binuklearen Bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato))‐Komplexen des CuII,NiII, ZnII,CdII und PdII

Synthesis, Structure and EPR Investigations of binuclear Bis(N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato)) Complexes of Cu^II, Ni^II, Zn^II, Cd^II and Pd^II The synthesis of binuclear Cu^II‐, Ni^II‐, Zn^II‐, Cd^II‐ and Pd^II‐complexes of the quadridentate ligand N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and the crystal structures of the Cu^II‐ and Ni^II‐complexes are reported. The Cu^II‐complex crystallizes in two polymorphic modifications: triclinic, (Z = 1) and monoclinic, P2₁/c (Z = 2). The Ni^II‐complex was found to be isostructural with the triclinic modification of the copper complex. The also prepared Pd^II‐, Zn^II‐ and Cd^II‐complexes could not be characterized by X‐ray analysis. However, EPR studies of diamagnetically diluted Cu^II/Pd^II‐ and Cu^II/Zn^II‐powders show axially‐symmetric g and A ^Cu tensors suggesting a nearly planar co‐ordination within the binuclear host complexes. Diamagnetically diluted Cu^II/Cd^II powder samples could not be prepared. In the EPR spectra of the pure binuclear Cu^II‐complex exchange‐coupled Cu^II‐Cu^II pairs were observed. According to the large Cu^II‐Cu^II distance of about 7,50Å a small fine structure parameter D = 26·10^?4 cm^?1 is observed; T‐dependent EPR measurements down to 5 K reveal small antiferromagnetic interactions for the Cu^II‐Cu^II dimer. Besides of the dimer in the EPR spectra the signals of a mononuclear Cu^II species are observed whose concentration is T‐dependent. This observation can be explained assuming an equilibrium between the binuclear Cu^II‐complex (Cu^II‐Cu^II pairs) and oligomeric complexes with “isolated” Cu^II ions.