Anja Recknagel

Neodym(III)komplexe mit stark raumerfüllenden Cyclopentadienyl- und Benzamidinat-Liganden: Ein Vergleich

Abstract [Cp** 2 Nd(μ-CI)] 2 ( 1 ) has been prepared by treatment of NdCI 3 (THF) 2 with two equivalents of KCp** (Cp** = 1,3-di-t-butylcyclopentadienyl). Similarly, Li[(CF) 3 ) 3 C 6 H 2 C(NSiMe 3 ) 2 ] reacts with NdCl 3 (THF) 2 to give [(CF 3 ) 3 C 6 H 2 C(NSiMe 3 ) 2 ] 2 Nd(μ-Cl) 2 Li(THF) 2 ( 2 ). Recrystallization of 2 from DME/hexane yields the binuclear derivative (μ-DME)[{(CF 3 ) 3 C 6 H 2 C(NSiMe 3 ) 2 } 2 Nd(μ-Cl) 2 Li(THF)] 2 ( 3 ). The molecular structures of 1 , 2 and 3 have been determined by X-ray diffraction. The 2,4,6-trisub- stituted benzamidinate anion [(CF 3 ) 3 C 6 H 2 C(NSiMe 3 ) 2 ] − can be regarded as a steric equivalent of bulky cyclopentadienyl ligands such as Cp* or Cp**.

Organolanthanid(II)chemie: Reaktionen von CP 2 Sm(THF)2 mit 1,4-diazadienen und cyclooctatetraen

Abstract Cp★ 2 SM(THF) 2 reacts with 1,4-diazadienes (DAD) to give 1:1-adducts of the type Cp★ 2 Sm(DAD). The molecular structure of Cp★ 2 Sm( t BuNCHCHN t Bu) ( 2 ) has been determined by X-ray crystallography. These complexes can be described as Cp★ 2 Sm III derivatives of the diazadiene radical anions as indicated by spectroscopic and structural data. Treatment of Cp★ 2 Sm(THF) 2 with 2-pyridinealdazine yields the binuclear complex (μ-C 12 H 10 N 4 )[Cp★ 2 Sm] 2 ( 5 ). Cyclooctatetraene reacts with Cp★ 2 Sm(THF) 2 to give the known compound Cp★Sm(COT)(THF) ( 6 ).

Diiminophosphinate des Lithiums, Samariums und Ytterbiums: Moleku¨lstrukturen von Li[Ph2P(NSiMe3)2](THF)2 und [Ph2P(NSiMe3)2]2Sm(μ-I)2Li(THF)2

Abstract The molecular structure of Li[Ph2P(NSiMe3)2](THF)2 (2) has been determined by an X-ray diffraction study. A four-membered LiNPN ring forms the central unit of the monomeric molecule. YbI2 reacts with two equivalents of Li[Ph2P(NSiMe3)2] (1) to give the novel ytterbium(II)diiminophosphinate [Ph2P(NSiMe3)2]2Yb(THF)2 (3). A similar reaction of 1 with SmI2 affords the samarium(III) derivative [Ph2P(NSiMe3)2]2Sm(μ-I)2Li(THF)2 (4) whose structure has also been determined by an X-ray diffraction study.

Struktur und reaktivität von ytterbiumbenzamidinaten

Abstract The ytterbium(II) benzamidinates [RC6H4C(NSiMe3)2]2Yb(THF)2 (1a: R  H, 1b: R  OMe) react with diaryl diselenides and ditellurides to give ytterbium(III) complexes of the type [RC6H4C(NSiMe3)2]2Yb(SeR′)(THF) (2: R  H, R′  Ph; 3: R  H, R′  Mes) and [RC6H4C-(NSiMe3)2]2Yb(TeR′)(THF) (4: R  OMe, R′  Mes), respectively. The molecular structure of [PhC(NSiMe3)2]2Yb(SeMes)(THF) (3) has been determined by X-ray crystallography (triclinic, space group P 1 , a 1064.9(3), b 1377.1(3), c 3690(3) pm, α 68.61(2), β 89.46(3), γ 72.82(1)°, Z = 4, 10531 observed reflexions, R = 0.045). Moreover the strongly temperature-dependent 1H NMR spectra of 2 and 3 are discussed and 171Yb NMR spectra of some ytterbium(II) chelate complexes are reported.

Monomere Organosamarium(III) Chalkogenolate durch reduktive Spaltung von E–E-Bindungen (E = S, Se, Te)

Abstract The THF adduct of decamethylsamarocene, CP ★ 2 Sm(THF) 2 , reacts with disulfides, diselenides and ditellurides to give organosamarium(III) complexes containing a SmE bond (E = S, Se, Te). The molecular structures of the complexes CP ★ 2 Sm(S 2 CNMe 2 ) ( 1 ), Cp ★ 2 Sm[TeC 6 H 2 Me 3 -2,4,6](THF) ( 4 ) and Cp ★ 2 Sm[SeC 6 H 2 (CF 3 ) 3 -2,4,6](THF) ( 5 have been determined by X-ray diffraction.

Nichtklassische organolanthanoid(II)komplexe: Darstellung und reaktivität der ersten organoneodym(II)verbindung

Abstract NdCl 2 (THF) 2 reacts with KCp ★ to give [K(THF) n ] 2 [Cp 2 ★ NdCl 2 ] ( 1 ) which represents the first divalent organoneodymium complex. Treatment of 1 with t BuCl, [Me 2 NC(S)S] 2 or MesSeSeMes affords the organoneodymium(III) complexes Cp 2 ★ NdCl(THF) ( 2 ), Cp 2 ★ Nd(S 2 CNMe 2 ) ( 3 ) and Cp 2 ★ NdSeMes(THF) ( 4 ) (Cp ★ = η 5 - pentamethylcyclopentadienyl).

Synthese von Metallacyclophosphazenen mit Praseodym, Neodym, Uran und Thorium *

Abstract Li[Ph 2 P(NSiMe 3 ) 2 ] ( 1 ) reacts with anhydrous lanthanide and actinide chlorides to give metallacyclophosphazene derivatives, which contain a four-membered metalladiazaphosphetidine ring. The complexes [Ph 2 P(NSiMe 3 ) 2 ] 2 MCl ( 3 : M = Pr, 4 : M = Nd), [Ph 2 P(NSiMe 3 ) 2 ] 2 MCl 2 ( 5 : M = U, 6 : M = Th) and [Ph 2 P(NSiMe 3 ) 2 ] 2 UO 2 ( 7 ) were isolated. Treatment of UCl 4 with Li[t-Bu 2 P(NSiMe 3 ) 2 ] ( 2 ) yields green crystalline [t-Bu 2 P(NSiMe 3 ) 2 ] 2 UCl 2 ( 8 ).

Alkoxysilylamide des Neodyms, Samariums und Ytterbiums: Viergliedrige anorganische Ringsysteme in der Lanthanidchemie

Abstract Li[Me 2 Si(O t Bu)(N t Bu)]( 1 ) reacts with YbI 2 to give the ytterbium(II)alkoxysilylamide [Me 2 Si(O t Bu)-(N t Bu)] 2 Yb (THF) 2 ( 2 ). The analogous reactio of 1 with SmI 2 yields the samarium(III) derivative [Me 2 Si(O t Bu)(N t Bu)] 2 Sm(μ-I) 2 Li(THF) 2 ( 3 ). Moreover, the preparation of [Me 2 Si(O t Bu)(N t Bu)] 3 Nd ( 4 ) and [Me 2 Si(O t Bu)(N t Bu)] 2 Yb(μ-Cl) 2 Li(THF) 2 ( 5 ) is described. The molecular structures of 4 and 5 have been determined by X-ray crystallography.

Inorganic Ring Systems Containing Lanthanide Elements

Abstract Lanthanide complexes containing fourmembered N-C-N-Ln, N-S-N-Ln and N-P-N-Ln rings have been synthesized by treatment of lanthanide halides with bulky anionic chelating ligands. Similar ring systems containing four different elements (N-Si-0- Ln) have been obtained by reacting anhydrous lanthanide trichlorides with Li[Me2Si(OtBu)(NtBu)]. A twelve-membered inorganic ring is formed during the reaction of Cp∗2Sm(THF)2 with [Cp∗Fe(CO)2]2.