Lanthanides metal complexes with

Figure 3.2S The structure of (a) [Dy(H20)(DTPA)] and (b) [Dy2(DTPA)2] [Dy, black (large balls) O, grey N, black (small balls) C, white H, omitted)]. (Redrawn from the CIF files of J. Wang et al, Syntheses and structural determinations of the nine-coordinate rare earth metal Na4[Dy "(dtpa)(H20)]2 l6H20, Na[Dy "(edta)(H20)3]-3.25H20 and Na3[Dy (nta)2(H20)]-5.5H20, Journal of Coordination Chemistry, 60 (20), 2221-2241, 2007 [106] and Y. Inomata, T. Sunakawa and F.S. HoweU, The syntheses of lanthanide metal complexes with diethylenetriamine-N, N, N, N", N"-pentaacetic acid and the comparison of their crystal structures, Journal of Molecular Structure, 648 (1-2), 81-88, 2007 [107].)...

Inomata, Y, Sunakawa, T., and Howell, F.S. (2007) The syntheses of lanthanide metal complexes with diethylenetriamine-N, N, N, N",N"-pentaacetic acid and the comparison of their crystal structures. Journal of Molecular Structure, 648 (1-2), 81-88. 

Different chiral transition- and lanthanide-metal complexes can catalyze the cycloaddition reaction of unactivated and activated aldehydes with especially activated... 

Different main-group-, transition- and lanthanide-metal complexes can catalyze the cycloaddition reaction of activated aldehydes with activated and non-activated dienes. The chiral metal complexes which can catalyze these reactions include complexes which enable substrates to coordinate in a mono- or bidentate fashion. 

The aim of this chapter is to review the chemistry of chalcogenolates in the last 10 years. The more recent reviews in this field included chalcogenolates of the s-block elements,13,14 early transition metal thiolates,15 metal complexes with selenolate and tellurolate ligands,16 copper(I), lithium and magnesium thiolates,17 functionalized thiolate complexes,18 19 pentafluorobenzenethiolate platinum group compounds,20 tellurium derivatives,21 luminescent gold compounds,22 and complexes with lanthanide or actinide.23... 

Coordination compounds composed of tetrapyrrole macrocyclic ligands encompassing a large metal ion in a sandwich-like fashion have been known since 1936 when Linstead and co-workers (67) reported the first synthesis of Sn(IV) bis(phthalocyanine). Numerous homoleptic and heteroleptic sandwich-type or double-decker metal complexes with phthalocyanines (68-70) and porphyrins (71-75) have been studied and structurally characterized. The electrochromic properties of the lanthanide pc sandwich complexes (76) have been investigated and the stable radical bis(phthalocyaninato)lutetium has been found to be the first example of an intrinsic molecular semiconductor (77). In contrast to the wealth of literature describing porphyrin and pc sandwich complexes, re-... 

The kinetics of the hydrolysis of di(2,4-dinitrophenyl) phosphate (DDNPP) were studied in basic solutions buffered with Bis-Tris propane (BTP) in the presence of La3+, Sm3+, Tb3+, and Er3+. Two equivalents of the 2,4-dinitrophenolate ion were liberated for each equivalent of DDNPP and the reaction showed first-order kinetics. Potentiometric titrations showed the formation of dinuclear complexes such as [Ln2(BTP)2(OH) ](6 " i, with values of n varying as a function of pH for all studied metals. Hence the catalytic effect depends on the formation of dinuclear lanthanide ion complexes with several hydroxo ligands.97... 

Ans. No. Other mechanisms (radical, heterolytic, etc.) may be available with transition metal complexes. With lanthanide complexes in the highly stable 3 + oxidation state, an OA/RE-based mechanism is not possible. 

In contrast to the alkali metals, the lanthanides do not form crown ether complexes readily in aqueous solution, due to the considerable hydration energy of the Ln + ion. These complexes are, however, readily synthesized by operating in non-aqueous solvents. Because many studies have been made with lanthanide nitrate complexes, coordination numbers are often high. Thus 12-coordination is found in La(N03)3(18-crown-6) (Eigure 4.4), 11 coordination in La(N03)3(15-crown-5), and 10 coordination is found in La(N03)3(12-crown-4). Other complexes isolated include Nd(18-crown-6)o.75(N03)3, which is in fact [ Nd(18-crown-6)(N03)2 +]3 psid(N03)6]. Other lanthanide salts complex with crown ethers small crowns like 12-crown-4 give 2 1 complexes with lanthanide perchlorates, though the 2 1 complexes are not obtained with lanthanide nitrates where the anion can... 

Having arrived at uranium as the coordinated metal, we are already past the lanthanides. It is necessary to take a break here and turn towards rare earth metal complexes with amino functionalised carbenes. Amongst the earliest examples are samarium and yttrium complexes of our already familiar amino functionalised imidazolium zwitteiion from Figure 4.28. 

The interaction of a lanthanide metal with a substrate such as 3-hexyne could occur in several ways 60) by it complex formation, by oxidative addition into a C—H bond, or by reduction involving radical species. Subsequent lanthanide metal vapor studies were designed to test some of these possibilities. Co-condensation of lanthanide metal vapor with reagents containing acidic hydrogen atoms, e.g., terminal alkynes, demonstrated that oxidative addition of C—H was a viable reaction [Eqs. (32) and (33)] 51). These reactions also provided access to a new class of... 

Capping the square-like motif of [Ln4(p,4-OH)] with a fifth metal atom results in a square-pyramidal unit of Ln5((jt4-OH), a pentanuclear building block frequently observed in lanthanide hydroxide complexes with diketonate ligands. One such example is [Dy5( X4-OH)( X3-OH)4( x,Ti -Ph2acac)4(Ti -Ph2acac)6] (Ph = phenyl) whose structure is shown in Figure 6.35 [25, 80]. 

Transmetallation is a more convenient method to obtaining divalent organolanthanide complexes from lanthanide metals. Reaction of lanthanide metal powder with a mercury alkyl or aryl complex affords the corresponding divalent lanthanide complex (Equation 8.28) [94]. The preparation of divalent perfluorophenyl lanthanide complexes Ln(C6F5)2(THF) (Ln = Eu, n = 5 Ln = Yb, n=4) is a typical example. In most cases, the addition of a small amount of Lnl3 leads to acceleration of the reaction [95]. 

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