bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chirotopic and Stereogenic Metal Centers in [M(L)(L')(‘RS4’)] Complexes with Chiral Thioether‐Thiolate Ligands ‘RS4’‐H2 [‘MeS4’2− = 1,2‐bis(2‐mercaptophenylthio)propanato(2‐), ‘CH3(CH2)2S4’2− = 1,2‐bis(2‐mercaptophenylthio)pentanato(2‐), ‘HO(CH2)9S4’2−10
Authors: Sellmann Dieter , Bail Petra , Knoch Falk , Moll Matthias 
Published: July 2007

AbstractIn order to investigate the stereochemistry of substitution reactions of chiral pseudo‐octahedral complexes the chiral thioether‐thiolate ligands ‘RS4’‐H2 (= HSC6H4SCHRCH2‐SC6H4SH) with R = CH3‐ (5), CH3(CH2)2‐ (6), HO(CH2)9‐ (7), and PhCH2‐ (8) were synthesized by template alkylation of Na2[Ni(‘S2’)2] [‘S2’2− = 1,2‐benzenedithiolate(2‐)] with 1,2‐dibromoalkanes BrCHRCH2Br (R = CH3‐, 1; R = CH3(CH2)2‐, 2; R = HO(CH2)9‐, 3; R = PhCH2‐, 4) and isolated after hydrolyses. Reactions of ‘RS4’‐H2 with [RuCl2(PPh3)3] or [Mo(O)2(acac)2] yielded [Ru(PPh3)2(‘RS4’)] (R = CH3‐, 9; R = HO(CH2)9‐, 10; R = PhCH2‐, 11) and [Mo(O)2(‘MeS4’)] (12). [Ru(PPh3)2(‘MeS4’)] · 2 CH2Cl2 (9 · 2 CH2Cl2) and [Mo(O)2(‘MeS4’)] (12) were characterized by X‐ray structure determination. In both complexes, the metal centers are surrounded pseudo‐octahedrally by four sulfur donors of the ‘MeS4’ ligand and two cis coligands. The methyl substituent at the stereogenic C* atom of the C2 bridge of the ‘MeS4’ ligands assumes an equatorial position. In addition, the metal centers of these complexes are chirotopic and prostereogenic. Crystal data of 9 · 2 CH2Cl2 in comparison with [Ru(PBu3)2(‘S4’) 11‐bis(2‐mercaptophenylthio)‐1‐undecanolato(2‐), ‘PhCH2S4’2−1,2‐bis(2‐mercaptophenylthio)‐3‐phenylpropanato(2‐)] ] and those of 12 in comparison with [Mo(O)2(‘S4’)] show that distances and angles of the coordination cores are not influenced by the substituents on the C2 bridge. Reactions of the [Ru(PPh3)2(‘RS4’)] complexes (9–11) with the achiral substrates CO and PMe3, however, yielded diastereomers of [Ru(PPh3)(L)(‘RS4’)] (L = CO, R = CH3‐, 13; L = CO, R = HO(CH2)9‐, 14; L = CO, R = PhCH2‐, 15; L = PMe3, R = CH3‐, 16; L = PM R = HO(CH2)9‐, 17; L = PMe3, R = PhCH2‐, 18) in diastereomeric excesses between 60 and 82%. The diastereomer of [Ru(PPh3)CO)(‘MeS4’)] (13) which could be characterized by X‐ray structure determination exhibits the CO ligand in trans position to the thioether donor which is bound to the stereogenic C* atom of the C2 bridge. Reaction of 9 · 2 CH2Cl2 with the optically pure bidentate diphosphine (+)‐(S,S)‐DIOP [= (+)‐2,3‐O‐isopropylidene‐2,3‐dihydroxy‐1,4‐bis(diphenylphosphino)butane] yielded 1:1 mixtures of two diastereomers of [Ru(DIOP)(‘MeS4’)] (19) one of which was separated in pure form by HPLC.
Chiral Organometallic Reagents, XIV. Theoretical Investigations into the Mechanism of Inversion of Configuration at the Carbon Center of α‐Sulfur‐Substituted Carbanions
Authors: Dress Ruprecht K. , Rölle Thomas , Hoffmann Reinhard W. 
Published: July 2007

AbstractAb initio calculations showed that the two elementary steps in the racemization of the α‐methylthioethyl anion (7), inversion of the pyramidal anionic center, and rotation around the C−S bond, occur in sequence and are not concerted. The former process passes over a barrier of 1.1 kcal/mol, the latter over one of 10.9 kcal/mol. MNDO calculations on the α‐phenylthioethyl anion (8) revealed a preferred conformation of the S‐aryl bond, allowing maximum delocalization of the sulfur lone pairs into the π* orbital of the aryl group. This orientation is maintained during rotation around the C−S bond and is the origin of steric hindrance in the racemization of certain α‐arylthio‐, α‐arylseleno‐, and α‐aryltelluroalkyllithium compounds 1 to 6.
A T‐Shaped Selenenyl Halide: Synthesis and Characterisation of a Proposed Reaction Intermediate
Authors: Jones Peter G. , Ramírez Arellano M. C. De 
Published: July 2007

AbstractThe T‐shaped selenenyl halide (1), which may be regarded as a model substance for the transition state in nucleophilic displacement at divalent chalcogen atoms, has been isolated and subjected to X‐ray structure determination.
N,N′ ‐Disilylated 1,4‐Dihydropyrazines: Organosilyl Substitution Reactions, Structural Effects of Steric Hindrance, and Electron Exchange with C60
Authors: Lichtblau Alexander , Ehlend Anja , Hausen H.‐D. , Kaim Wolfgang 
Published: July 2007

AbstractOrganosilyl exchange reactions of the extremely electronrich and formally “antiaromatic” 1,4‐bis(trimethylsilyl)‐substituted 1,4‐dihydropyrazine 1 with Ph3SiCl or Me5Si2Cl yielded the new compounds 2 and 3 with triarylsilyl and disilanyl substituents. At δ = 4.53 in CDCl3 compound 3 shows a particularly high‐field shifted 1H‐NMR resonance for the 1,4‐dihydropyrazine protons. In contrast to the planar ring arrangement of 1,4‐bis(triisopropylsilyl)‐1,4‐dihydropyrazine 4, the crystal structure determination of the 2,5‐dimethylated analogue 5 as obtained by reductive silylation exhibits a pronounced boat conformation of the heterocycle due to steric repulsion between the substituents, the closest H…H (CH3/ CH) contact being 211 pm. Despite the sizeable structural differences between 4 and 5 both compounds are reversibly oxidized at very negative potentials, at ‐0.90 and ‐0.85 V vs. Fc+/0, respectively, It appears that the electrochemical behavior of this class of compounds is determined ***primarly by the configuration at the nitrogen centers and less by the ring conformation. Compound 4 reacts with C60 under EPR‐detectable electron exchange to afford 4+* and C. The radical cation 4+* generated separately via oxidation with iodine was characterized by low‐temperature UV/Vis and ENDOR spectroscopy. An ENDOR spectrum revealing silylalkyl coupling was also obtained for the related radical cation of reversibly oxidizable 1,1′ ‐bis(tert‐butyldimethylsilyl)‐1,1′,4,4′ ‐bipyridylidene (8).
Zinc Complexes of S,N Ligands Derived from Thiazolines
Authors: Brand Udo , Vahrenkamp Heinrich 
Published: July 2007

AbstractThree different thiazoline derivatives or their tautomeric mercaptoethylamine derivatives were used for the preparation of zinc complexes containing S,N ligands. 2‐(2‐pyridyl)‐3‐(2‐pyridylmethyl)‐1,3‐thiazolidine (PPMT) could not be opened reductively but acted as a tridentate nitrogen ligand in (PPMT)ZnX2 (1a, b, X = Br, NO3). The thiazolidine tautomer N‐(2‐mercaptoethyl)salicylideneimine (MESIH2) yielded polymeric (MESI)Zn (2) and, after oxidation, monomeric (MESI)2Zn (3) containing a disulfide unit. The 2‐aryl‐benzo‐1,3‐thiazoline tautomers N‐(2‐mercaptophenyl)‐p‐fluoroben‐zylideneimine (MPFBH) and N‐(2‐mercaptophenyl)‐p‐meth‐oxybenzylideneimine (MPMBH) underwent reaction with diethyl zinc resulting in the unstable L . Zn‐Et complexes 4a and b, which are probably dimeric and the stable 2:1 complex (MPFB)2Zn (5). The structures of 3 and 5 were determined and were found to exhibit distorted tetrahedral ZnN2O2 and ZnN2S2 coordinations, respectively.
Transition‐Metal‐Substituted Gallanes: Synthesis and Spectroscopic Studies of Highly Polar σ(M—Ga) Bonds, Structures of trans‐(Ph3P)(CO)3Co—Ga[(CH2)3N(C 2H5)2]R (R = Cl, CH3) and (n5‐C5H5)(CO)2Fe—GaCl2 [N(CH3)3]
Authors: Fischer Roland A. , Miehr Alexander , Priermeier Thomas 
Published: July 2007

AbstractThe salt elimination reaction of the transition carbonyl metal‐lates [L(CO)nM](Na/K) (M = Cr, Mo, W, Mn, Re, Fe, Co, Ni; L= CO, n5‐C5R5, PR3; n= 1‐4; R= alkyl, aryl) with the base‐stabilized galliumhalides ClaGaR3 ‐a(Do) (R = H, alkyl, halide; Do = THF, N(CH3)3, NC7H13) or ClaGa[(CH2)3N‐R2](R)2 ‐ a yielded almost quantitatively the transition metal‐substituted, gallanes [L(CO)nM]aGaR3 ‐ a(Do) and [L(CO)n‐M]aGa[(CH2)3NR2](R)2 ‐ a, respectively. Residual halide functionalities in these complexes were selectively replaced by various other groups. The new compounds were characterized by means of elemental analysis, 1H‐, 13C‐, 31P‐NMR, MS, and lR v(CO) data. The single‐crystal X‐ray structure analysis of trans‐(Ph3P)(CO)3Co‐Ga[(CH2) 3N(C2H5)2](R)( 6s: R = Cl, 6t: R= CH3) showed s̀(Co‐Ga) lengths of 237.78(4) and 249.5(1) pm, respectively. A short s̀(Fe‐Ga) contact of 236.18(3) pm was found for (n5‐C5H5)(CO)2Fe‐Ga‐Cl2[N(CH 3)3] (5a). Low‐pressure MOCVD experiments were performed to give thin films of analytically pure CoGa alloy.
Synthesis of 7‐Alkyl/aryl‐1,3,5‐triaza‐7‐phosphonia‐adamantane Cations and Their Reductive Cleavage to Novel N‐Methyl‐P‐alkyl/aryl[3.3.1]bicyclononane Ligands
Authors: Assmann Bernd , Angermaier Klaus , Paul Martin , Riede Jürgen , Schmidbaur Hubert 
Published: July 2007

AbstractTwo reaction pathways for the synthesis of 1,3,5‐triaza‐7‐phosphoniaadamantane salts, RP[(CH2)6N3]+X‐ (1), were followed. Route 1 starts with commercial tetrakis(hydroxymethyl)phosphonium chloride, which is converted into P(CH2OH)3 by treatment with a base. Subsequent quaternization with alkyl halides RX and cyclization with formaldehyde and ammonia afford [R‐TPA]+X‐. This process is only applicable for R = Me (1a) and Et (1b), however. Route 2 is more general and starts with primary phosphanes RPH2, which are converted into organotris(hydroxymethyl)phosphonium salts with formaldehyde and hydrochloric acid followed by ring closure with CH2O/NH3 to give compounds 1c–1f (R = t‐Bu, c‐Hex, Bz, and Ph, respectively, and X = Cl, I, PF6, or BPh4). Reductive cleavage of compounds 1 by sodium in liquid ammonia proceeds with either external (P‐R) or internal (P‐CH2) bond rupture. P‐R cleavage affords the 1,3,5–triaza‐7‐phosphaadamantane (TPA), while cage cleavage leads to new bowl‐ or helmet‐shaped ligand systems with peripheral amine and phosphane functions (2). Yields of the cage‐opening reaction are highest for R = Ph (2f), moderate for R = Me and Et (2a, 2b), and poor with the remaining R groups (2c–2e). A radical mechanism is proposed for this reaction, the leaving group properties of R determining the direction of the cleavage. The crystal and molecular structures of compounds 2a and 2f were determined by X‐ray diffraction studies. Exo positions were found for the N‐Me and P‐R groups. The isomers with the R group in the endo position are also present in solution in small amounts, as detected by NMR spectroscopy. Isomer interconversion by P inversion is slow on the NMR time scale. Compounds 2a, 2b and 2f were oxidized with elemental sulfur and selenium to give the monosulfides and selenides, respectively (2aS, 2aSe, 2bS, 2bSe, 2fS, 2fSe). Oxidation with H2O2 led to degradation. Compound 2a was quaternized at the P atom by treatment with Mel to give the corresponding phosphonium salt. Treatment with equimolar quantities of (Me2S)AuCl led to the 1:1 complexes 2aAucl, 2bAuCl and 2fAuCl, with the AuCl units solely P‐bonded, as determined by X‐ray diffraction of 2aAuCl and 2fAuCl. Compound 2a forms an ionic 2:1 complex with AuCl, composed of the ions [(2a)2Au]+ Cl‐ (with unidentate ligands), while its reaction with [Me2AuCl]2 leads to [Me2Au(2a)]+ [Me2AuCl2]‐ (with a chelating 2a ligand), as again confirmed by crystal structure analysis in both cases. Ligands 2a, 2b and 2f also act as chelating ligands in their tetracarbonylmolybdenum complexes obtained in the reactions with (C7H8)Mo(CO)4.
1,1‐Hydroborierung von Alkinen mit 6‐Aza‐nido‐decaboranen
Authors: Meyer Franc , Schmidt Martin U. , Paetzold Peter 
Published: July 2007

1,1‐Hydroboration of Alkynes with 6‐Aza‐nido‐decaboranes[1]Alkynes ACCR′ (R′ = Me, Bu, tBu, SiMe3), that contain a mobile group A, like H or SiMe3, undergo hydroboration by 6‐aza‐nido‐decaboranes RNB9H11 (1a‐c, R = H, Ph, PhCH2) and 1,2‐migration of the group A, to give the corresponding 9‐(1‐alkenyl)‐6‐aza‐nido‐decaboranes RNB9H10(CH=CR′A) (2a‐h). Ethenes AHC=CH2 (A = SiMe3, SnBu3) are hydroborated by 1a, b as well to form products of the type RNB9H10(CH2CH2A) (3a‐c). The alkyne Me3SiCCH undergoes a hydroboration with 1b twice; the formation of (PhNB9H10)2CHCH2SiMe3 (4) proceeds by a 1,1‐ and a 1,2‐hydroboration step, apparently. The crystal structure analysis of (PhCH2)NB9H10[CH=CMe(SiMe3)] (2e; space group Pl) reveals a (Z configuration of the ethene moiety.
Laboratory Scale Direct Synthesis of Pure AuF3
Authors: Tornieporth‐Oetting Inis C. , Klapötke Thomas M. 
Published: July 2007

AbstractPure AuF3 has been prepared in high yield from the elements in a convenient and safe one‐pot laboratory scale reaction. The identity and purity was clearly established by vibrational spectroscopy, mass spectrometry and microanalytical data.
Synthesis and Reactivity of Silicon‐Transition Metal Complexes, 3l. Metallosilanols and Metallosiloxanes, 6. Die ersten Hydroxysilandiyl‐verbrückten Zweikernkomplexe: Selektive Oxygenierung der Silicium‐Brücke in Silandiyleisen‐Komplexen mit Dimethyldioxiran
Authors: Malisch Wolfgang , Hindahl Kathrin , Käb Harald , Reising Joachim , Adam Waldemar , Prechtl Frank 
Published: July 2007

Synthesis and Reactivity of Silicon‐Transition Metal Complexes, 31 — Metallosilanols and Metallosiloxanes, 6. — The First Hydroxysilanediyl‐Bridged Binuclear Complexes: Selective Oxofunctionalization of the Silicon Bridge in Silanediyliron Complexes with DimethyldioxiraneOxygenation of [μ‐(R)(H)Si][Fe(CO)2Cp]2 [R = Me (1a), pTol (1b)] with dimethyldioxirane (2) yields the μ‐(hydroxysilanediyl)bisiron complexes [μ‐(R)(HO)Si][Fe(CO)2Cp]2 [R = Me (3a), pTol (3b)]. In an analogous manner the cyclic complex (μ‐OC)[μ‐(Mes)(H)Si][Fe(CO)Cp]2(Fe‐Fe) (6) obtained by photochemical reaction of Cp(OC)2Fe‐Me (4) with MesSiH3, (5) is converted into (μ‐OC)[μ‐(Mes)(HO)Si][Fe(CO)Cp]2‐(Fe‐Fe) (7). 6 and 7 are obtained as a mixture of cis(Mes), cis(H or OH), and trans isomers.
Tri‐tert‐butylazadiboriridin: Ringerweiterung mit Isonitrilen, α‐Bromlithioalkanen und Aziden
Authors: Luckert Stefan , Eversheim Ellen , Müller Matthias , Redenz‐Stormanns Burkhard , Englert Ulli , Paetzold Peter 
Published: July 2007

Tri‐tert‐butylazadiboriridine: Ring Prolongation by the Action of Isonitriles, α‐Bromolithioalkanes, and AzidesIsonitriles ArNC are 1,1‐boroborated by the B‐B bond of the azadiboriridine (‐BR‐BR‐NR‐) (1; R = tBu) to form the four‐membered ring [‐BR‐C(NAr)‐BR‐NR‐] (2b; Ar = 2,6‐C6H3Me2). Corresponding rings undergo [3 + 3] cyclodimerization of the B‐C=N chain to give the tricyclic products 6a, b when isonitriles RNC with the small ligands R = Me, Et are boroborated by 1. Two molecules of tBuNC open the B‐B bond of 1; the resulting five‐membered ring 7a may add excess tBuNC to yield 7a · 2 CNtBu (8). The results strongly support a mechanistic hypothesis set up for the multistep reaction of 1 and CO. The carbene units, which are present in the α‐bromolithioalkanes [‐C(Br)Li‐CMe2‐CH2‐], LiC(Br)H2, and LiC(Br)Me2, are also 1,1‐boroborated by 1 to give the corresponding four‐membered ring 2c, or by a 2:1 reaction to afford the five‐membered ring 7b, or by a 1:1 reaction and subsequent rearrangement to yield the five‐membered ring 7c. The nitrene units, which are present in the azides PhN3 and PhCH2N3, are also boroborated by 1; the diazadiboretidines 5b, c are formed with evolution of N2. The bis(diazadiboretidinyl)borane RB(N2B2R3)2 (5d) is the corresponding product from the reaction of RB(N3)2 with 1 in the ratio 1:2. The azide Me3SiN3 reacts differently yielding the N‐boryl diazadiboretidine 5e and the iminoborane RB≡N̊. The B‐B bond length of 187.6 pm in 5e indicates a transannular bonding interaction. The products 5d, 5e, and 6a were characterized by a crystal structure analysis.
Highly Substituted Tris(pyrazolyl)methane Ligands and Some Zinc Complexes Thereof
Authors: Titze Christoph , Hermann Jörg , Vahrenkamp Heinrich 
Published: July 2007

AbstractTris(pyrazolyl)methane ligands in which two or three of the pyrazole carbon atoms bear organic substituents (L1‐L7) were synthesized from chloroform and the corresponding pyrazole under phase transfer conditions. Their behavior towards zinc salts was found to span the range from no reaction at all to hydrolytic destruction. One hydrolysis product isolated and structurally characterized was the perchlorate complex [(HPz5)3Zn‐OClO3]ClO4 (1), other ones were the 2:1 complexes (HPz3)2ZnBr2 (2) and (HPz6)2Zn(NO3)2 (3, HPzn = substituted pyrazole). Zinc perchlorate and tris(trimethylpy‐razolyl)methane (L2) formed the octahedral binary complex [L22Zn](ClO4)2 (4) as evidenced by a structure determination. Zinc halides produced the 1:1 complexes L1 · ZnBr2 (5), L4 · ZnCl2 (6), and L4 · ZnBr2 (7), which according to the structure determinations of 6 and 7 contain tetrahedral ZnN2Hal2 units with only bidentate tris(pyrazolyl)methane ligands. In contrast, the zinc nitrate complex L4 · Zn(NO3)2 (8) was found to have an octahedral structure with mono‐ and bidentate nitrate and tridentate L4. The bromide complex 7 was converted by silver perchlorate hydrate into the labile compound [L4 · ZnBr]ClO4 (9) and then into the unstable product [L4 · Zn‐OH2](ClO4)2 (10), both presumed to contain zinc in a tetrahedral ZnN3Br or ZnN3O environment, respectively. The ease of hydrolytic self‐destruction prevented the exploitation of the reactivity of 9 and 10 in analogy to that of the corresponding tris(pyrazolyl)borate zinc complexes.
Metal Complexes with Tetrapyrrole Ligands, LXIX. Facile Synthesis and 13C‐NMR Spectrum of Dichloro(octaethylporphyrinato)zirconium(IV)
Authors: Buchler Johann W. , Eberle Mike 
Published: July 2007

AbstractThe synthesis of dichloro(2,3,7,8,12,13,17,18‐octaethylpor‐phyrinato)zirconium(IV), Zr(oep)Cl2, from zirconium tetrachloride and octaethylporphyrin, H2(oep), is described. The reported synthesis is a new and simple route to this precursor of organometallic compounds. Zr(oep)Cl2 was characterized by elemental analyses, 1H‐ and 13C‐NMR, UV/Vis, and mass spectra. Hydrolysis yielded a mixture of mono‐ and binuclear hydroxy zirconium(IV) porphyrins.
Octacarbonylbis {μ‐(tris(trimethylsilyl)methyl]indany l} dimanganese with Two Monoalkyl Indium Groups Bridging the Mn–Mn Bond
Authors: Uhl Werner , Keimliling Sven Uwe , Hiller Wolfgang , Neumayer Markus 
Published: July 2007

AbstractTetrahedra‐tetrakis[tris(trimethylsilyl)methyl]tetraindane(4) (1) reacts with decacarbonyldimanganese(0) to yield the bright red crystalline title compound 2, in which two carbonyl ligands are replaced by two InR fragments. The crystal structure determination of 2 shows two Mn(CO)4 groups (Mn‐Mn 313.7 pm) bridged by two monoalkylindium units and a planar Mn2In2 molecular center.
Tethered 2,2′‐Bipyridine Ligands — Synthesis and Coordination Properties
Authors: König Burkhard 
Published: July 2007

AbstractBis‐2,2′‐bipyridine ligands tethered by phthalic‐ and tere‐phthalic esters were synthesized. The coordination with copper(I) and silver(I) ions gave mononuclear complexes. With terepthalic acid as a spacer between 2,2′‐bipyridines 2 + 2 assemblies were identified in traces. The coordination compounds were investigated by electrospray mass spectroscopy.
[Cp4Fe4(E2)2] Clusters with Triangulated Dodecahedral Fe4E4 Skeletons (E = P, As)
Authors: Scherer Otto J. , Kemény Gunther , Wolmershäuser Gotthelf 
Published: July 2007

AbstractThe thermolysis of [CpFe(CO)2]2 (1) and P4 or As4 affords the iron clusters [Cp4Fe4(E2)2], E = As (2a), P (2b), the Fe4E4 skeleton of which consists of a triangulated dodecahedron. S8 and gray Se oxidize the P2 ligands of 2b with formation of [Cp4Fe4(P2X2)2], X = S (3a), Se (3b), complexes with the hitherto unknown P2X2 ligands, 2a, b and 3a, b have been characterized by X‐ray crystallography.
Öffnung des Aza‐closo‐dodecaboran‐Gerüsts durch Basen
Authors: Lomme Petra , Meyer Franc , Englert Ulli , Paetzold Peter 
Published: July 2007

Opening of the Aza‐clso‐dodecaborane Skeleton by BasesThe aza‐closo‐borane PhNB11H11 (1a) is opened by the amines NR3 (R = Me, Et) to give the novel aza‐nido‐dodecaboranes PhNB11H11(NR3) (2a, b). The non‐planar open pentagonal face of 2a, b accomodates the N atom, a BHB bridge, and the base‐bound B atom, according to NMR spectra and the crystal structure analysis of monoclinic 2b. A similar but more symmetric structure is found when closo‐RNB11H11 (1a‐c, R = Ph, Me, H) is attacked by anionic bases X− to give nido‐RNB11H11X− (3a‐j; R/X = Me/H, Me/F, Me/Cl, Ph/OH, H/OMe, Me/OMe, Me/OtBu, Me/NEt2, Me/Me, Me/Bu). The anions are precipitated with cations [K([18]crown‐6)], [S(NMe2)3], [N(PPh3)2], [Et2NH2], or [Li(tmeda)2]. The nido‐structures of type 2 and 3 are derived from the hypothetical closo‐NB12H13.
The Chemistry of 1,3,5‐Triazacyclohexane Complexes, 3. High Yield Synthesis of [Cr{N(SiMe3)2}3] and Accurate Structure Determination by Cocrystallization with Me6Si2
Authors: Köhn Randolf D. , Kociok‐Köhn Gabriele , Haufe Matthias 
Published: July 2007

AbstractThe reaction of N,N′,N′′‐trimethyl‐1,3,5‐triazacyclohexane chromium trichloride ((Me3TAC)CrCl3, 1) with LiN(SiMe3)2 or NaN(SiMe3)2 in petroleum ether yields nearly quantitatively [Cr{N(SiMe3)2}3] (2) with loss of the Me3TAC ligand. Compound 2 could be crystallized from hexamethyldisilane as [Cr{N(SiMe3)2}3] · (Me6Si2)0,5 which allowed the refinement of the X‐ray crystal structure in the trigonal space group P‐31c (no. 163) (a = 16.012(3) Å, c = 8.4796(12) Å, V = 1882.8(6) Å3, Z = 2) without severe disorder.
The First Selective Cage Redistribution Reaction of P4O6
Authors: Strojek Stephan , Jansen Martin 
Published: July 2007

AbstractReaction of tetraphosphorus hexaoxide with organic azides leads selectively to the cage redistribution products1P4O6NPh,2P4O6NC2H4Ph,3P4O6NSO2CH3,4P4O6NC6H13, and5P4O6NCO2C2H5by nitrene insertion. The molecular structure consists of an adamantane‐like P4O5N cage with a terminally bound oxygen atom. The P4O5N cagelike structure is confirmed by31P NMR spectroscopy and X‐ray structure analysis. The P4O5N cages of the P4O6NR molecules possess a significant geometrical distortion.
Metal Complexes with Tetrapyrrole Ligands, LXX. Synthesis, Characterization, and Variable‐Temperature 1H‐NMR Investigations of Cerium(IV) and Zirconium(IV) Double‐Deckers Derived from 2,3,7,8,12,13,17,18‐Octaethyl‐5‐methylporphyrin
Authors: Buchler Johann W. , Heinz Georg 
Published: July 2007

AbstractThe synthesis of bis(2,3,7,8,12,13,17,18‐octaethyl‐5‐methyl‐porphyrinato)cerium(IV) and ‐zirconium(IV) [M(oemep)2; M = Ce, Zr, respectively] is described. The complexes were characterized by UV/Vis and IR spectroscopy and cyclic volt‐ammetry. 1H‐NMR spectra of the new cerium and zirconium sandwich complexes show that they exist as a mixture of vicinal and transversal isomers due to the rigid square‐antipri‐smatic coordination geometry found in metal(IV) bis(porphy‐rinates). From the temperature dependence of the 1H‐NMR spectra the rotational rigidity of the double‐decker system was deduced. In toluene, free rotation of the two porphyrin macrocycles with respect to each other does not occur up to 373 K.