Synthesis of a new class of compounds containing a Ln-O-Al moiety has been accomplished by the reaction of LAlOH(Me) (L = HC(CMeNAr)(2), Ar = 2,6-iPr(2)C(6)H(3)) with a series of Cp(3)Ln compounds. The terminal Al-OH group shows selective reactivity, and the complexes Cp(2)Ln(THF)-O-AlL(Me) (Ln = Yb, 1; Er, 2; Dy, 3), Cp(2)Yb-O-AlL(Me) (4), and Cp(3)Ln(mu-OH)AlL(Me) (Ln = Er, 5; Dy, 6; Sm, 7) were obtained. This allows further insight into the proton exchange process, and two different mechanisms, intermolecular and intramolecular elimination of CpH, are proposed under different conditions. Complexes 1-4, 6, and 7 have been characterized by X-ray structural analyses which reveals a Ln-O-Al or Ln(mu-OH)Al core in these complexes. The obtuse Ln-O-Al angles fall in the range 151.9-169.8 degrees . The reaction of 1 or 4 with Me(3)SnF in toluene under refluxing conditions unexpectedly yielded the compounds [Cp(2)Yb(mu-OSnMe(3))](2) (8) and LAl(Me)F (9). Reactions of LAlOH(Me) with the mono- and dicyclopentadienyl complexes LYbCp(Cl) (10) and LYbCp(2) (11) supported by the bulky beta-diketiminate ligand were unsuccessful. However, the reaction of LAl(OH)Me with LYbN(SiMe(3))(2)Cl (12) containing a labile Yb-N bond leads to the formation of LYbCl-O-AlL(Me) (13) under elimination of HN(SiMe(3))(2). Furthermore, complexes 1, 3, 4, and 6 exhibit good catalytic activity for the polymerization of epsilon-caprolactone.

The reaction of beta-diketiminated aluminum(I) monomer LAl with a large bulky azide N3Ar' (L = HC(CMeNAr)2, Ar' = 2,6-Ar2C6H3, Ar = 2,6-iPr2C6H3) in the temperature range from -78 degrees C to room temperature affords two different isomers 2 and 3, which have been characterized by spectroscopic and X-ray structural analyses, as well as elemental analysis. The variable-temperature 1H NMR kinetic studies of this reaction indicate the existence of the monomer LAlNAr' (1) at low temperature and the thermal stability of the compounds increases in the order of 1 < 2 < 3.

An aluminum oxide [LAlO]2 (1) has been prepared by the oxidative addition of aluminum(I) monomer LAl (L = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3) with molecular oxygen. The short Al-O bonds in Al2(mu-O)2 result in short Al...Al contacts and subsequent steric crowding of the Ar substituents from the two oriented L. 1 hydrolyzes to form [LAl(OH)]2(mu-O) (2). A C-H-activated aluminum hydroxide 4, an isomer of 1, however, is obtained by hydrolysis of the bulky aluminum amide 3 rather than by a conversion by high temperature treatment of 1. This indicates selective preparation of isomers 1 and 4.

This paper reports on the synthesis, X-ray structure, magnetic properties, and DFT calculations of [[HC(CMeNAr)2]Mn]2 (Ar = 2,6-iPr2C6H3) (2), the first complex with three-coordinate manganese(I). Reduction of the iodide [[HC(CMeNAr)2]Mn(mu-I)]2 (1) with Na/K in toluene afforded 2 as dark-red crystals. The molecule of 2 contains a Mn2(2+) core with a Mn-Mn bond. The magnetic investigations show a rare example of a high-spin manganese(I) complex with an antiferromagnetic interaction between the two Mn(I) centers. The DFT calculations indicate a strong s-s interaction of the two Mn(I) ions with the open shell configuration (3d54s1). This suggests that the magnetic behavior of 2 could be correctly described as the coupling between two S1 = S2 = 5/2 spin centers. The Mn-Mn bond energy is estimated at 44 kcal mol(-1) by first principle calculations with the B3LYP functional. The further oxidative reaction of 2 with KMnO4 or O2 resulted in the formation of manganese(III) oxide [[HC(CMeNAr)2]Mn(mu-O)]2 (3). Compound 3 shows an antiferromagnetic coupling between the two oxo-bridged manganese(III) centers by magnetic measurements.

The aluminum chloride iodide LAlClI (2, L = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3) has been synthesized to study the stepwise hydrolysis of this compound in the presence of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene as hydrogen halide acceptor. The isolation and characterization of the aluminum chloride hydroxide [LAlCl(μ-OH)]2 (3) and the dihydroxide LAl(OH)2 (4) demonstrate the realization of a controlled hydrolysis.

Not all down‐to‐Earth: A stable aluminacyclopropene LAl(η2‐C2H2) 1 was isolated from the reaction of LAl with C2H2. Further reaction of 1 with C2H2 results in terminal CCH and CHCH2 groups at the Al center. The end‐on insertion of an azide into one AlC bond in 1 leads to the first aluminaazacyclobutene 2. These reactions can be considered prebiotic, as AlI species and acetylene are found in outer space.

Reaction of the β-diketiminate lithium salt LLi(OEt 2 ) (1) (L ) HC(CMeNAr) 2 , Ar ) 2,6-iPr 2 C 6 H 3 ) with MnCl 2 in diethyl ether provided the metalate complex LMn(µ-Cl) 2 Li(OEt 2 ) 2 (3) in high yield. The dimeric compound [LMn(µ-Cl)] 2 (4) free of alkaline salt was obtained when the β-diketiminate potassium salt LK (2) was used instead of 1. The substitution reactions of 4 with CpNa, MeLi, and PhLi resulted in the formation of organomanganese complexes LMnCp(THF) ( 7), [LMn(µ-Me)] 2 (8), and LMnPh (9), respectively. The novel ionic compound [LMnCl 2 ][{C(Me)N(iPr)} 2 CH] (6) was obtained, when the N-heterocyclic carbene {C(Me)N(iPr)} 2 C was used as a proton acceptor. The first doubly carboxylato-bridged complex with four-coordinate manganese(II), [LMn(µ-O 2 CMe)] 2 (5), was synthesized from the reaction of 2 and Mn(O 2 CMe) 2 in THF. Complexes 3-7 were characterized by single-crystal X-ray structural analysis. The structures show that the β-diketiminate ligand backbone is essentially planar and the metal centers reside in distorted tetrahedral geometry.

The reaction of an aluminacyclopropene LAl[eta2-C2(SiMe3)2] (1, L = HC(CMeNAr)2, Ar = 2,6-iPr2C6H3) with CS2 in the temperature range from -78 degrees C to room temperature affords the first seven-membered aluminum sulfur-containing heterocyclic compound [LAl]2(mu-S)[eta2-SC(SiMe3)=C=C(SiMe3)] (2) bearing an allenyl group. The structural characterization of 2 and the analogous compound LAl[OC(O)C2(SiMe3)2] (3) of the proposed intermediate A and the variable-temperature 1H NMR kinetic study of this reaction may give a better understanding on this unusual conversion.