Unsupported gold(I)-copper(I) interactions through eta1 Au-[Au(C6F5)2]- coordination to Cu+ Lewis acid sites

The reaction of the complex [Au2Ag2(C6F5)4)N[triple bond]CCH3)2]n (1) with 1 equiv of CuCl in the presence of 1 equiv of pyrimidine ligand leads to the formation of the heteronuclear Au(I)-Cu(I) organometallic polymer [Cu{Au(C6F5)2}(N[triple bond]CCH3)(mu2-C4H4N2)]n (2) through a transmetalation reaction. Complex 2 displays unprecedented unsupported Au(I)...Cu(I) interactions of [Au(C6F5)2]- units with the acid Cu(I) sites in a [Cu(N[triple bond]CCH3)(mu2-pyrimidine)]n+(n) polymeric chain. Complex 2 has a rich photophysics in solution and in the solid state.     

Do aurophilic interactions compete against hydrogen bonds? Experimental evidence and rationalization based on ab initio calculations

[M(C6F5)(N(H)=CPh2)] (M = Ag (1) and Au (2)) complexes have been synthesized and characterized by X-ray diffraction analysis. Complex 1 shows a ladder-type structure in which two [Ag(C6F5)(N(H)=CPh2)] units are linked by a Ag(I)-Ag(I) interaction in an antiparallel disposition. The dimeric units are associated through hydrogen bonds of the type N-H...F(ortho). On the other hand, gold(I) complex 2 displays discrete dimers also in an antiparallel conformation in which both Au(I)-Au(I) interactions and N-H.F(ortho) hydrogen bonds appear within the dimeric units. The features of these coexisting interactions have been theoretically studied by ab initio calculations based on four different model systems in order to analyze them separately. The interactions have been analyzed at HF and MP2 levels of theory showing that, in this case, even at larger distances. The Au(I)-Au(I) interaction is stronger than Ag(I)-Ag(I) and that N-H.F hydrogen bonding and Au(I)-Au(I) contacts have a similar strength in the same molecule, which permits a competition between these two structural motifs giving rise to different structural arrangements.     

Syntheses and solid-state and solution structures of [Ba[(C5Me5)2Ti2F7]2(hmpa)] and [Ba8Ti6F30I2(C5Me5)6(hmpa)6][I3]2

The complexes [Ba[(C5Me5)2Ti2F7]2(hmpa)].(THF), 1.hmpa.(THF), and [Ba8Ti6F30I2(C5Me5)6(hmpa)6][I3]2.10(THF), 2[I3]2.10(THF), were prepared from [Hdmpy](+)[(C5Me5)2Ti2F7]- (dmpy = 2,6-dimethylpyridine), BaI2, and hmpa (hmpa = hexamethylphosphoramide). They were characterized by 1H and 19F NMR and IR spectroscopy and examined by single-crystal X-ray crystallography. The complexation equilibrium of the barium ion in 1 with hmpa and the dynamics of the barium ion moving on the fluorine surfaces of [(C5Me5)2Ti2F7]- in 1.hmpa have been studied by variable-temperature 19F NMR spectroscopy. The core of the complex 2[I3]2.10(THF) resembles the basic structural unit of the cubic perovskite.     

Crystal structure of CF3I(Cl)F

In addition to CF3IF2 and CF3ICl2, CF3I(Cl)F is the only known example of the (trifluoromethyl)iodine dihalides. CF3I(Cl)F is even at low temperatures not stable in solution and decomposes by symmetrization. It crystallizes in the orthorhombic space group Cmca with a = 6.898(1) A, b = 7.310(1) A, c = 20.127(1) A and eight formula units per unit cell. The final R indices [I > 2 sigma(I)] are R1 = 0.0372 and wR2 = 0.0981.     

Competing ion decomposition channels in matrix-assisted laser desorption ionization

We gauged the internal energy transfer for two dissociative ion decomposition channels in matrix-assisted laser desorption ionization (MALDI) using the benzyltriphenylphosphonium (BTP) thermometer ion [PhCH 2PPh 3] (+). Common MALDI matrixes [alpha-cyano-4-hydroxycinnamic acid (CHCA), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SA), and 2,5-dihydroxycinnamic acid (DHB)] were studied with nitrogen laser (4 ns pulse length) and mode-locked 3 x omega Nd:YAG laser (22 ps pulse length) excitation. Despite the higher fluence required to initiate fragmentation, BTP ions indicated lower internal energy transfer with the picosecond laser in all three matrixes. These differences can be rationalized in terms of phase explosion induced by the nanosecond laser vs a stress-confinement-driven desorption mechanism for the picosecond laser. For the two ion production channels of the BTP thermometer ion, breaking a single bond can result in the formation of benzyl/tropylium ions, F1, or triphenylphosphine ions, F2. In SA and DHB, as well as in CHCA at low fluence levels, the efficiency of these channels (expressed by the branching ratio I F1/ I F2) is moderately in favor of producing tropylium ions, 1 < I F1/ I F2 < 6. As the laser fluence is increased, for CHCA, there is a dramatic shift in favor of the tropylium ion production, with I F1/ I F2 approximately 30 for the nanosecond and the picosecond laser, respectively. This change is correlated with the sudden increase in the BTP internal energies in CHCA in the same laser fluence range. The large changes observed in internal energy deposition for CHCA with laser fluence can account for its ability to induce fragmentation in peptides more readily than SA and DHB.     

Copper(I) complexes of fluorinated triazapentadienyl ligands: synthesis and characterization of [N[(C3F7)C(Dipp)N]2]CuL (where L = NCCH3, CNBut, CO; Dipp = 2,6-diisopropylphenyl)

Sterically demanding triazapentadiene [N[(C3F7)C(Dipp)N]2] H has been synthesized in good yield. It features a W-shaped ligand backbone in the solid state. [N[(C3F7)C(Dipp)N]2]H reacts with copper(I) oxide in acetonitrile leading to [N[(C3F7)C(Dipp)N]2]CuNCCH3. This copper adduct serves as an excellent precursor to obtain thermally stable [N[(C3F7)C(Dipp)N]2]CuCNBut and [N[(C3F7)C(Dipp)N]2]CuCO. IR spectroscopic data of these copper(I) isocyanide (CN = 2176 cm(-1)) and copper(I) carbonyl (CO = 2109 cm(-1)) complexes indicate that the [N[(C3F7)C(Dipp)N]2]- ligand is a fairly weak donor.     

Preparation of highly fluorinated cyclopropanes and ring-opening reactions with halogens

Various highly fluorinated cyclopropanes 1 were prepared by reaction of the appropriate fluorinated olefins with hexafluoropropylene oxide (HFPO) at 180 degrees C. The fluorinated nitrile 1e was converted to the triazine derivatives 2a and 2b by catalysis with Ag(2)O and NH(3)/(CF(3)CO)(2)O, respectively. The fluorinated cyclopropanes reacted with halogens at elevated temperatures to provide the first useful, general synthesis of 1,3-dihalopolyfluoropropanes. At 150-240 degrees C, hexafluorocyclopropane and halogens X(2) produce XCF(2)CF(2)CF(2)X (X = Cl, Br, I) in 50-80% isolated yields. Pentafluorocyclopropanes c-C(3)F(5)Y [Y = Cl, OCF(3), OC(3)F(7) and OCF(2)CF(CF(3))OCF(2)CF(2)Z; Z = SO(2)F, CN, CO(2)Me] react regiospecifically at 150 degrees C to give XCF(2)CF(2)CFXY, c-C(3)F(5)Br reacts regioselectively with Br(2) to give a 16.7:1 mixture of BrCF(2)CF(2)CFBr(2):BrCF(2)CFBrCF(2)Br, whereas c-C(3)F(5)H reacts unselectively with I(2) to produce a statistical 2:1 mixture of ICF(2)CF(2)CFHI:ICF(2)CFHCF(2)I. Tri- and di(pentafluorocyclopropyl) derivatives 2 also undergo ring-opening reaction with halogens to give 16 and 17. Upon treatment of tetrafluorocyclopropanes 1j, 1k, and 1l with Br(2) or I(2), ring opening occurred exclusively at substituted carbons to give XCF(2)CF(2)CXY(2). Thermolysis of the ring-opened product ICF(2)CF(2)CFIOR(F) at 240 degrees C gave R(F)I and ICF(2)CF(2)COF in high yields.     

CRYSTAL STRUCTURE OF COMPLEX OF p-METHOXY-ARYLDIAZONIUM SALT WITH DTBENZO-24-CROWN-8

<正> Mr=448.5, monoclinic P21/c, a=8.531(3), B=12.076(4), C=33.309(13) A, β=95.41(1)°, V=3416.2(2) A3, Z=4, μ(MoKα)= 1.2 cm-1, F(000)=1408, room temperature, R=0.086, Rw=0.084 (W=1/(σ2(F) + 0.0001 x F2)) for 1759 independent reflections with I > 3σ(I).     

266 nm photolysis of CF3I and C2F5I studied by diode laser gain FM spectroscopy

Frequency modulated diode laser based absorption at 1.315 microm has been used to measure the Doppler lineshapes of the I((2)P(1/2)-(2)P(3/2)) transition in atomic iodine produced from the 266 nm photolysis of both CF(3)I and C(2)F(5)I. Wavelength resolved laser gain is seen following photolysis as excited iodine atoms ((2)P(1/2)) are produced with a quantum yield close to unity from photolysis of both parent molecules. Time resolved measurements were made and the nascent speed distribution and translational anisotropy parameter, beta were determined. Mean atomic speeds of 800 and 850 ms(-1), which correspond to 83 and 68% of the maximum possible kinetic energy release into the iodine photofragment, were determined for photolysis of CF(3)I and C(2)F(5)I, respectively. The nascent translational anisotropy parameter was found to be beta = 1.77 +/- 0.05 for CF(3)I and beta = 1.69 +/- 0.05 for C(2)F(5)I. These values are explicable in terms of parent rotational motion and non-adiabatic processes in the exit channel.     

温控分子动力学研究微管蛋白活性肽链的折叠机制

运用温控和常温分子动力学方法, 研究了微管蛋白活性部位Pep1-28肽链的折叠机制, 总模拟时间为380.0 ns. 对于温控分子动力学, 逐渐降温可以清晰显示Pep1-28肽链的折叠途径, 发生明显折叠的温度约为550 K, 其折叠和去折叠可逆机制为U(>1200 K)←→I1(1200-1000 K)←→I2(800 K)←→I3(600 K)←→I4(450 K)←→F1(400 K)←→F2(300 K), 其中U为去折叠态构象, I1、I2、I3和I4是折叠过程中的四个重要的中间态构象, F1和F2是两个结构相近的折叠态构象. 对于常温(300 K)分子动力学, 其构象转变和折叠过程相当迅速, 很难观察到有效、稳定的中间态构象. 尤其引人注意的是, 其折叠态结构陷入了能量局域极小点, 与温控(300 K)的有较大差异, 两者能量差高达297.53 kJ·mol-1. 可见, 温控分子动力学方法不仅清晰地显示多肽和蛋白质折叠过程的重要中间态构象, 为折叠和去折叠机制提供直接、可靠的依据, 而且还有助于跨越较高的构象能垒, 促使多肽和蛋白质折叠以形成全局能量最低的稳定结构.     

Toluene-sandwiched trinuclear copper(I) and silver(I) triazolates and phosphine adducts of dinuclear copper(I) and silver(I) triazolates

Cu (I) and Ag (I) complexes of the fluorinated triazolate ligand [3,5-(C3F7)2Tz](-) have been synthesized using the corresponding metal(I) oxides and the triazole. They form pi-acid/base adducts with toluene, leading to [Tol][M3][Tol] ([Tol]=toluene; [M3]={[3,5-(C3F7)2Tz]Cu}3 or {[3,5-(C3F7)2Tz]Ag}3) type structures. Packing diagrams show the presence of extended chains of the type {[Tol][M3][Tol]}infinity, but the intertoluene ring distances are too long for significant pi-arene/pi-arene contacts. These copper and silver triazolates react with PPh3 (at a 1:1 metal ion/P molar ratio), leading to dinuclear {[3,5-(C3F7)2Tz]Cu(PPh3)}2 and {[3,5-(C3F7) 2Tz]Ag(PPh3)}2. They feature a six-membered Cu(mu-N-N) 2Cu or Ag(mu-N-N)2Ag core with a boat conformation.     

Amalgamating at the molecular level. A study of the strong closed-shell Au(I)···Hg(II) interaction

Complex {[Hg(C(6)F(5))(2)][Au(C(6)F(5))(PMe(3))](2)}(n)2 displays unsupported Au(I)···Hg(II) and Au(I)···Au(I) interactions. Its crystal structure displays a polymeric -(Au-Hg-Au-Au-Hg-Au)(n)- disposition. Ab initio calculations show very strong Au(I)···Hg(II) and Au(I)···Au(I) closed-shell interactions of -73.3 kJ mol(-1) and -57.0 kJ mol(-1), respectively, which have a dispersive (van der Waals) nature and are strengthened by large relativistic effects (>20%).     

Synthesis and Crystal Structure of a New Penta-coordinated Cu(Ⅱ) Complex:Cu(C17H13F3O3)2·C5H5N

A new copper(Ⅱ) complex 3,Cu(C17H13F3O3)2·C5H5N,has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic,space group C2/c with a = 17.8511(7),b = 17.4136(7),c = 13.9425(7) ,β = 124.4830(10)°,V = 3572.5(3) 3,Z = 4,C39H29CuF6NO6,Mr = 785.17,F(000) = 1604,T = 292(2) K,Dc = 1.460 g/cm3 and μ = 0.691 mm-1. The structure was refined to R = 0.0477 and wR = 0.1110 for 2935 observed reflections with I > 2σ(I). For the title compound,X-ray analysis reveals that the copper(II) is penta-coordinated by four oxygen atoms from the corresponding 1-(4-(benzyloxy)phenyl)-4,4,4-trifluorobutane-1,3-dione ligands and one nitrogen atom of pyridine,forming a distorted square pyramidal geometry. It is found that the trifluoromethyl group,F(1)/F(1'),F(2)/F(2') and F(3)/F(3')),is disordered over two orientations in an approximate 3:1 ratio.     

The First Organoxenon(IV) Compound: Pentafluorophenyldifluoroxenonium(IV) Tetrafluoroborate

Xenon(IV) - carbon bonding has been realized for the first time in the product formed from the reaction of XeF(4) with C(6)F(5)BF(2) in CH(2)Cl(2) at -55 degrees C [Eq. (1)]. [C(6)F(5)XeF(2)][BF(4)] is a strong oxidative fluorinating agent. This xenon(IV) compound fluorinates (C(6)F(5))(3)P to (C(6)F(5))(3)PF(2), C(6)F(5)I to C(6)F(5)IF(2), and I(2) to IF(5). In all cases, [C(6)F(5)Xe][BF(4)] was obtained as a by-product.     

Syntheses of highly fluorinated 1,3,5-triazapentadienyl ligands and their use in the isolation of copper(I)-carbonyl and copper(I)-ethylene complexes

Fully fluorinated triazapentadienyl ligand [N{(C3F7)C(C6F5)N}2]- and the related [N{(C3F7)C(2-F,6-(CF3)C6H3)N}2]- have been synthesized in good yield via a convenient route and used in the isolation of three- and four-coordinate copper(I)-carbon monoxide complexes. They show fairly high nu(CO) values (>2100 cm(-1)), indicating the presence of electron-poor Cu sites. The copper(I)-ethylene adduct [N{(C3F7)C(C6F5)N}2]Cu(C2H4), featuring a three-coordinate Cu site, has also been synthesized using [N{(C3F7)C(C6F5)N}2]CuNCCH3 and C2H4.     

Soluble mu-Fi bridged niobium clusters: synthesis and crystal structures of (Et4N)6[Nb6Fi6Bri6(NCS)a6]Br2 and Cs1.6K2.4[Nb6Fi6Ii6(NCS)a6

Two new anions [Nb(6)F(i)(6)X(i)(6)(NCS)(a)(6)](4-)(X = Br, I) based on octahedral niobium clusters with edge-bridging F ligands have been prepared by reaction of Cs(3)Nb(6)F(6)Br(12) and Cs(4)Nb(6)F(8.5)I(9.5) with aqueous solution of KSCN. The anions were isolated as (Et(4)N)(6)[Nb(6)F(6)Br(6)(NCS)(6)]Br(2) (1)and Cs(1.6)K(2.4)[Nb(6)F(6)I(6)(NCS)(6)] (2) salts.     

Unsymmetrical platinum(II) phosphido derivatives: oxidation and reductive coupling processes involving platinum(III) complexes as intermediates

Reaction of the trinuclear [NBu 4] 2[(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(R F) 2] ( 1, R F = C 6F 5) with HCl results in the formation of the unusual anionic hexanuclear derivative [NBu 4] 2[{(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(mu-Cl)} 2] ( 4, 96 e (-) skeleton) through the cleavage of two Pt-C 6F 5 bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu 4][(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(acac)] ( 5, 48 e (-) skeleton), which is oxidized by Ag (+) to form the trinuclear compound [(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(acac)][ClO 4] ( 6, 46 e (-) skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which displays a Pt-Pt bond. The reduction of 6 by [NBu 4][BH 4] gives back 5. The treatment of 6 with Br (-) (1:1 molar ratio) at room temperature gives a mixture of the isomers [(PPh 2R F)(R F)Pt(mu-PPh 2)(mu-Br)Pt(mu-PPh 2) 2Pt(acac)], having Br trans to R F ( 7a) or Br cis to R F ( 7b), which are the result of PPh 2/C 6F 5 reductive coupling. The treatment of 5 with I 2 (1:1 molar ratio) yields the hexanuclear [{(PPh 2R F)(R F)Pt(mu-PPh 2)(mu-I)Pt(mu-PPh 2) 2Pt(mu-I)} 2] ( 8, 96 e (-) skeleton), which is easily transformed into the trinuclear compound [(PPh 2R F)(R F)Pt(mu-PPh 2)(mu-I)Pt(mu-PPh 2) 2Pt(I)(PPh 3)] ( 9, 48 e (-) skeleton). Reaction of [(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(NCMe) 2] ( 10) with I 2 at 213 K for short reaction times gives the trinuclear platinum derivative [(R F) 2Pt(mu-PPh 2) 2Pt(mu-PPh 2) 2Pt(I) 2] ( 11, 46e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In particular, the (195)Pt NMR analysis, carried out also by (19)F- (195)Pt heteronuclear multiple-quantum coherence, revealed an unprecedented shielding of the (195)Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has been carried out.     

Cationic carbonyl complexes of rhodium(I) and rhodium(III): syntheses,vibrational spectra,NMR studies,and molecular structures of tetrakis(carbonyl)rhodium(I) heptachlorodialuminate and -gallate, [Rh(CO)4][Al2Cl7] and [Rh(CO)4][Ga2Cl7

Dimeric rhodium(I) bis(carbonyl) chloride, [Rh(CO)(2)(mu-Cl)](2), is found to be a useful and convenient starting material for the syntheses of new cationic carbonyl complexes of both rhodium(I) and rhodium(III). Its reaction with the Lewis acids AlCl(3) or GaCl(3) produces in a CO atmosphere at room temperature the salts [Rh(CO)(4)][M(2)Cl(7)] (M = Al, Ga), which are characterized by Raman spectroscopy and single-crystal X-ray diffraction. Crystal data for [Rh(CO)(4)][Al(2)Cl(7)]: triclinic, space group Ponemacr; (No. 2); a = 9.705(3), b = 9.800(2), c = 10.268(2) A; alpha = 76.52(2), beta = 76.05(2), gamma = 66.15(2) degrees; V = 856.7(5) A(3); Z = 2; T = 293 K; R(1) [I > 2sigma(I)] = 0.0524, wR(2) = 0.1586. Crystal data for [Rh(CO)(4)][Ga(2)Cl(7)]: triclinic, space group Ponemacr; (No. 2); a = 9.649(1), b = 9.624(1), c = 10.133(1) A; alpha = 77.38(1), beta = 76.13(1), gamma = 65.61(1) degrees; V = 824.4(2) A(3); Z = 2; T = 143 K; R(1) [I > 2sigma(I)] = 0.0358, wR(2) = 0.0792. Structural parameters for the square planar cation [Rh(CO)(4)](+) are compared to those of isoelectronic [Pd(CO)(4)](2+) and of [Pt(CO)(4)](2+). Dissolution of [Rh(CO)(2)Cl](2) in HSO(3)F in a CO atmosphere allows formation of [Rh(CO)(4)](+)((solv)). Oxidation of [Rh(CO)(2)Cl](2) by S(2)O(6)F(2) in HSO(3)F results in the formation of ClOSO(2)F and two seemingly oligomeric Rh(III) carbonyl fluorosulfato intermediates, which are easily reduced by CO addition to [Rh(CO)(4)](+)((solv)). Controlled oxidation of this solution with S(2)O(6)F(2) produces fac-Rh(CO)(3)(SO(3)F)(3) in about 95% yield. This Rh(III) complex can be reduced by CO at 25 degrees C in anhydrous HF to give [Rh(CO)(4)](+)((solv)); addition of SbF(5) at -40 degrees C to the resulting solution allows isolation of [Rh(CO)(4)][Sb(2)F(11)], which is found to have a highly symmetrical (D(4)(h)()) [Sb(2)F(11)](-) anion. Oxidation of [Rh(CO)(2)Cl](2) in anhydrous HF by F(2), followed in a second step by carbonylation in the presence of SbF(5), is found to be a simple, straightforward route to pure [Rh(CO)(5)Cl][Sb(2)F(11)](2), which has previously been structurally characterized by us. All new complexes are characterized by vibrational and NMR spectroscopy. Assignment of the vibrational spectra and interpretation of the structural data are supported by DFT calculations.     

Selenolate gold complexes with aurophilic Au(I)-Au(I) and Au(I)-Au(III) interactions

The gold(I) selenolate compound [Au(2)(SePh)(2)(mu-dppf)] (dppf = 1,1'-bis(diphenylphosphino)ferrocene) has been prepared by reaction of [Au(2)Cl(2)(mu-dppf)] with PhSeSiMe(3) in a molar ratio 1:2. This complex reacts with gold(I) or gold(III) derivatives to give polynuclear gold(I)-gold(I) or gold(I)-gold(III) complexes of the type [Au(4)(mu-SePh)(2)(PPh(3))(2)(mu-dppf)](OTf)(2), [Au(3)(C(6)F(5))(3)(mu-SePh)(2)(mu-dppf)], or [Au(4)(C(6)F(5))(6)(mu-SePh)(2)(mu-dppf)], with bridging selenolate ligands. The reaction of [Au(2)(SePh)(2)(mu-dppf)] with 1 equiv of AgOTf leads to the formation of the insoluble Ag(SePh) and the compound [Au(2)(mu-SePh)(mu-dppf)]OTf. The complexes [Au(4)(C(6)F(5))(6)(mu-SePh)(2)(mu-dppf)] and [Au(2)(mu-SePh)(mu-dppf)]OTf (two different solvates) have been characterized by X-ray diffraction studies and show the presence of weak gold(I)-gold(III) interactions in the former and intra- and intermolecular gold(I)-gold(I) inter-actions in the later.     

Syntheses,structures, and properties of the bis(cyclopentadienyl) rare-earth imidodiphosphinochalocogenido compounds Cp2Ln[N(QPPh2)2] (Ln = La,Gd, Er,or Yb for Q = Se; Ln = Yb for Q = S)

The compounds Cp2Ln[N(QPPh2)2] (Ln = La (1), Gd (2), Er (3), or Yb (4) for Q = Se, Ln = Yb (5) for Q = S) have been synthesized from the corresponding rare-earth tris(cyclopentadienyl) compound and H[N(QPPh2)2]. The structures of compounds 1, 2, 3, and 5, as determined by X-ray crystallography, consist of a Cp2Ln fragment, coordinated eta 3 through two chalcogen atoms and an N atom of the imidodiphosphinochalcogenido ligand [N(QPPh2)2]-. In compound 4, the Cp2Yb moiety is coordinated eta 2 through the two Se atoms of the [N(SePPh2)2]-ligand. 31P and 77Se (for 1) NMR spectroscopies lend insight into the solution nature of these species. Crystal data: 1, C34H30LaNP2Se2, triclinic, P1, a = 9.7959(10) A, b = 12.4134(13) A, c = 13.9077(14) A, alpha = 88.106(2) degrees, beta = 88.327(2) degrees, gamma = 68.481(2) degrees, V = 1572.2(3) A3, T = 153 K, Z = 2, and R1(F) = 0.0257 for the 5947 reflections with I > .2 sigma(I); 2, C34H30GdNP2Se2, triclinic, P1, a = 9.7130(14) A, b = 12.2659(17) A, c = 13.953(2) A, alpha = 88.062(2) degrees, beta = 87.613(2) degrees, gamma = 69.041(2) degrees, V = 1550.7(4) A3, T = 153 K, Z = 2, and R1(F) = 0.0323 for the 5064 reflections with I > 2 sigma(I); 3, C34H30ErNP2Se2, triclinic, P1, a = 9.704(2) A, b = 12.222(3) A, c = 13.980(4) A, alpha = 88.230(4) degrees, beta = 87.487(4) degees, gamma = 69.107(4) degrees, V = 1547.4(7) A3, T = 153 K, Z = 2, and R1(F) = 0.0278 for the 6377 reflections with I > 2 sigma(I); 4, C34H30NP2Se2Yb.C4H8O, triclinic, P1, a = 12.087(4) A, b = 12.429(4) A, c = 23.990(7) A, alpha = 89.406(5) degrees, beta = 86.368(5) degrees, gamma = 81.664(5) degrees, V = 3558.8(18) A3, T = 153 K, Z = 4, and R1(F) = 0.0321 for the 11,883 reflections with I > 2 sigma(I); and 5, C34H30NP2S2Yb, monoclinic, P21/n, a = 13.8799(18) A, b = 12.6747(16) A, c = 17.180(2) A, beta = 91.102(3) degrees, V = 3021.8(7) A3, T = 153 K, Z = 4, and R1(F) = 0.0218 for the 6698 reflections with I > 2 sigma(I).