ライフサイエンスコーパス: Hf

1 Hf-, Sn-, and Zr-Beta zeolites catalyze the cross-aldol

2 Hf-NU-1000-ZrBn is found to be a promising single-compon

3 )N)(3)M(mu-H)(mu-NMe(2))(2)](2)M (M = Zr, 1; Hf, 2) were observed to be intermediates and characteriz

4 Reactions of d0 amides M(NMe2)4 (M = Zr, 1; Hf, 2) with O2 have been found to yield unusual trinucle

5 fined correlation between the Th/Hf and (176)Hf/(177)Hf ratios in chondrites that reflects remobiliza

6 08,207,206)Pb/(204)Pb, (143)Nd/(144)Nd, (176)Hf/(177)Hf, and (230)Th/(232)Th.

7 Evidence of (176)Hf excess in select meteorites older than 4556Ma was sug

8 rrelation between the Th/Hf and (176)Hf/(177)Hf ratios in chondrites that reflects remobilization of

9 06)Pb/(204)Pb, (143)Nd/(144)Nd, (176)Hf/(177)Hf, and (230)Th/(232)Th.

10 actions define distinct initial (182)Hf/(180)Hf corresponding to a 13.8 +/- 5.3 million year apparent

11 scopy between Stark-Zeeman sublevels in (180)Hf(19)F(+) with a coherence time of 100 milliseconds.

12 (182)Hf-(182)W chronometry of terrestrial rocks points to acc

13 Accurate (182)Hf-(182)W chronology of early planetary differentiation

14 lization of the lunar magma ocean after (182)Hf was no longer extant-that is, more than about 60 mill

15 adioisotopes (e.g., (26)Al, (41)Ca, and (182)Hf) synthesized in one or multiple stars and added to th

16 vertheless, some N-body simulations and (182)Hf-(182)W and (87)Rb-(87)Sr chronology of some lunar roc

17 The decoupling between (182)Hf and (26)Al requires distinct stellar origins: steady-

18 resulting from the decay of now-extinct (182)Hf, among five magmatic iron meteorite groups.

19 particular, the abundances inferred for (182)Hf (half-life = 8.9 million years) and (129)I (half-life

20 te galactic stellar nucleosynthesis for (182)Hf and late-stage contamination of the protosolar molecu

21 metal fractions define distinct initial (182)Hf/(180)Hf corresponding to a 13.8 +/- 5.3 million year

22 asymptotic giant branch stars produces (182)Hf.

23 In contrast, our results support (182)Hf homogeneity and chronological significance of the (18

24 on of the hafnium-tungsten systematics ((182)Hf decaying to (182)W and emitting two electrons with a

25 Using the (182)Hf-(182)W chronometer, we show that a FUN CAI recording

26 y and chronological significance of the (182)Hf-(182)W clock.

27 le, which can be investigated using the (182)Hf-(182)W decay system in shergottite-nakhlite-chassigni

28 The (182)Hf-(182)W system provides a powerful complement to the (

29 gen ligand, [(eta(5)-C(5)H(2)-1,2,4-Me(3))(2)Hf](2)(mu(2),eta(2),eta(2)-N(2)), by addition of CySiH(3

30 f (C(5)H(5))(2)Zr(CH(3))(2) or (C(5)Me(5))(2)Hf(CH(3))(2) with diphenyldiazomethane is limited to the

31 ted hafnocene product, (eta(5)-C(5)Me(4)H)(2)Hf(OTf)(N(2)(CH(3))) provides a platform for additional

32 yl diazenide compound, (eta(5)-C(5)Me(4)H)(2)Hf(OTf)(N(2)(CH(3))), arising from methylation of one of

33 the hafnocene complex [(eta(5)-C(5)Me(4)H)(2)Hf](2)(mu(2),eta(2),eta(2)-N(2)) underwent clean carbony

34 nd dinitrogen ligand, [(eta(5)-C(5)Me(4)H)(2)Hf](2)(mu(2),eta(2),eta(2)-N(2)), with two equivalents o

35 functionalization in [(eta(5)-C(5)Me(4)H)(2)Hf](2)(N(2)C(2)O(2)) was also accomplished with silanes

36 e oxamidide ligand in [(eta(5)-C(5)Me(4)H)(2)Hf](2)(N(2)C(2)O(2)) was explored due to the high symmet

37 (2)(N(2)C(2)O(2)) and [(eta(5)-C(5)Me(4)H)(2)Hf](2)(N(2)C(2)O(2)), prepared from CO-induced N(2) bond

38 for (C(5)Me(5))(2)MCl(2) (M = Ti, 1; Zr, 2; Hf, 3; Th, 4; U, 5), where we can directly compare a cla

39 e2)6(mu-NMe2)3(mu3-O)(mu3-ONMe2) (M = Zr, 3; Hf, 4) in high yields.

40 oup 4 difluorides (Cp2MF2, M = Ti 4a, Zr 5a, Hf 6a; Cp*2MF2, M = Ti 4b, Zr 5b, Hf 6b) are reported.

41 4a, Zr 5a, Hf 6a; Cp*2MF2, M = Ti 4b, Zr 5b, Hf 6b) are reported.

42 2-MIL-125(Ti), NH2-UiO-66(Zr) and NH2-UiO-66(Hf) are among the most studied MOFs for photocatalytic a

43 report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the

44 alogue of the face-centered cubic fcu UiO-67(Hf).

45 8)V*, Ni(8)W, Pd(8)Al(dagger), Pd(8)Fe, Pd(8)Hf, Pd(8)Mn, Pd(8)Mo*, Pd(8)Nb, Pd(8)Sc, Pd(8)Ta, Pd(8)T

46 Zn, Pd(8)Zr, Pt(8)Al(dagger), Pt(8)Cr*, Pt(8)Hf, Pt(8)Mn, Pt(8)Mo, Pt(8)Nb, Pt(8)Rh(dagger), Pt(8)Sc,

47 Here we report the rational design of a Hf-porphyrin nanoscale metal-organic framework, DBP-UiO,

48 ikely mechanism is hydration of the adsorbed Hf complex up to a coordination number of 7, followed by

49 ntegral alkyne units in a pair of Zr(4+) and Hf(4+) MOFs, which proceeds stereoselectively in a singl

50 ch as (t)BuNCO and CO(2) to form new N-C and Hf-O bonds.

51 the 40 elements: Ta, U, Ir, Rh, Th, Ce, and Hf showed the lowest Dmin values, </=10 nm; Bi, W, In, P

52 tentative correlation between S isotopes and Hf-W core segregation ages suggests that the two systems

53 oselectivity is observed, whereby Zr(IV) and Hf(IV) principally direct P-OR hydrolysis, whereas Th(IV

54 dimeric structure in the cases of Zr(IV) and Hf(IV).

55 y accelerated by Ce(IV), Th(IV), Zr(IV), and Hf(IV) cations.

56 discrepancy between the U-Pb (60-80 Myr) and Hf-W clocks (30 Myr) in determining the timescale of Ear

57 The Pb, Sr, Nd, and Hf isotopic mixing arrays show that the Archean EM I mat

58 requiring the separation of Sr, Pb, Nd, and Hf only.

59 by addition of CySiH(3) resulted in N-Si and Hf-H bond formation and a compound poised for subsequent

60 , B, Na, Ga, Rb, Sr, Zr, Nb, Cs, Ba, Sm, and Hf, allows more than 80% of correct predictions in leave

61 ically unsaturated diene complexes of Ti and Hf.

62 r and Pb, LREE then La-Ce-Nd-Sm, Lu(Yb), and Hf, Th, and U, respectively) along with an additional, i

63 crystallographic analysis reveals the Zr and Hf complexes to be closely isostructural; the bond lengt

64 The high atomic number of Zr and Hf in the SBUs serves as effective X-ray antenna by abso

65 sis of a series of 14 interpenetrated Zr and Hf MOFs linked by functionalized 4,4'-[1,4-phenylene-bis

66 e of UiO materials, the d-orbitals of Zr and Hf, are too low in binding energy and thus cannot overla

67 In addition, the WB4 alloys with Ti, Zr, and Hf showed a substantially increased oxidation resistance

68 s show that when group IV (i.e., Ti, Zr, and Hf) or V (i.e., Nb and Ta) transition metals are substit

69 number, in the order Ti > Zr approximately = Hf, and that uranium displays approximately half the cov

70 oys with 8 at. % Ti, 8 at. % Zr, and 6 at. % Hf gave hardness values, Hv, of 50.9 +/- 2.2, 55.9 +/- 2

71 s application to poorly characterized binary Hf systems, believed to be phase-separating, defines thr

72 old-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homoge

73 Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(3)-3-(t)Bu)Hf(I)(NCO), demonstrating that C-C bond formation is rev

74 2)Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(3)-(t)Bu)Hf](2)(mu(2), eta(2), eta(2)-N(2)), yields the correspon

75 Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(3)-3-(t)Bu)Hf](2)(N(2)C(2)O(2)) and [(eta(5)-C(5)Me(4)H)(2)Hf](2)(N

76 Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(3)-3-(t)Bu)Hf](2)(N(2)C(2)O(2)) with I(2) yielded the monomeric iod

77 Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(3)-3-(t)Bu)Hf](2)(N(2)C(2)O(2)), undergoes facile cycloaddition wit

78 ter 54 h in air at 530 degrees C achieved by Hf addition onto LSC.

79 Better by Hf: Anion coordination to a bridging hafnocene nitride c

80 llylic and homoallylic alcohols catalyzed by Hf(IV)-bishydroxamic acid (BHA) complexes is described.

81 d homoallylic amine derivatives catalyzed by Hf(IV)-bishydroxamic acid complexes is described.

82 As a multifunctional catalyst, Hf-NU-1000 is also efficient for other epoxide activatio

83 The hafnium analogue of 1, Cp*(Cl)Hf(2,3-dimethylbutadiene) (14), has been reported to giv

84 of the mixed-ring silyl methyl complex CpCp*Hf[Si(SiMe3)3]Me (4) with B(C6F5)3 in bromobenzene-d5 yi

85 Reactions of CpCp*Hf(SiR3)Me (SiR3 = SitBuPh2, SiHMes2) with B(C6F5)3 rapi

86 ary ligand, with the stabilities of the CpCp*Hf(SnPh(3))X compounds following the order X = NMe(2) >

87 p orbital mixing is enhanced for the diffuse Hf (5d) and Zr (4d) atomic orbitals in relation to the m

88 e orogenic processes which may have distinct Hf-Nd isotopic signatures.

89 ies (<10(-6) A/cm(2) at +/-2 V) and enhances Hf-SAND multilayer capacitance densities to nearly 1 muF

90 For example, Hf(OTf)4 mediates rapid endothermic ether right harpoon

91 . % for Ti, 10 at. % for Zr, and 8 at. % for Hf.

92 ion and silicate differentiation fractionate Hf from W.

93 rein a new Hf-based metal-organic framework (Hf-NU-1000) incorporating Hf6 clusters is reported.

94 mesoporous Hf-based metal-organic framework (Hf-NU-1000) is employed as a well-defined scaffold for a

95 ystem is much slower than that obtained from Hf-W systematics, and implies substantial accretion afte

96 titanium (Ti), zirconium (Zr), and hafnium (Hf), of different concentrations (0-50 at.

97 locked the plutonic archive through hafnium (Hf) and oxygen (O) isotope analysis of zoned zircon crys

98 Heavy Hf atoms in the SBUs efficiently absorb X-rays and trans

99 ands, enhanced intersystem crossing by heavy Hf centers, and facile (1)O2 diffusion through porous DB

100 bpy)3 ](2+) -derived tricarboxylate ligands (Hf-BPY-Ir or Hf-BPY-Ru; bpy=2,2'-bipyridine, ppy=2-pheny

101 Low Hf concentration films feature an aged surface of larger

102 U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe

103 Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimen

104 Lutetium-hafnium (Lu-Hf) isotope data for ALH indicate an igneous age of 4.09

105 esent an integrated zircon isotope (U-Pb, Lu-Hf, O) and trace element dataset from the paired Cu-Au (

106 The calculated Lu/Hf and Sm/Nd (samarium/neodymium) ratios of the ALH pare

107 from M6(mu3-O)4(mu3-OH)4(carboxylate)12 (M = Hf or Zr) secondary building units (SBUs) and anthracene

108 n-Bu, i-Bu, and 2-ethylbutyl (5a-f) and M = Hf; R = i-Bu and t-Bu (6 and 7, respectively)] is descri

109 This work suggests that MNiSn (M = Hf, Zr, Ti) and perhaps most other half-Heusler thermoel

110 (3)-N-N=CPh(2)](CH(3)) (M = Zr, R = H or M = Hf, R = CH(3)).

111 This new material Hf-NU-1000-ZrBn is fully characterized by a variety of s

112 A structurally well-defined mesoporous Hf-based metal-organic framework (Hf-NU-1000) is employe

113 ed compounds (M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta) with F-, H-, O-, and OH-functionalized surfaces

114 Here we report the clay-sized (<2 mum) Hf-Nd isotope data from Asian dust sources to better con

115 ](2-MeO[bond]C(6)H(4))(2,4,6-Me(3)C(6)H(2))N]Hf(CH(2)Ph) (3) (1), which is capable of polymerizing 1-

116 oxide-organic self-assembled nanodielectric (Hf-SAND) material consisting of regular, alternating pi-

117 y discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to di

118 d zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to sugges

119 Herein a new Hf-based metal-organic framework (Hf-NU-1000) incorporat

120 reconstructions and ground-truthed with new Hf-Nd isotope data, suggest that uppermost mantle at one

121 ore a comprehensive data set of isotopic (O, Hf) and chemical proxies in precisely U-Pb dated zircon

122 s-tert-butyl phenyl substituted complexes of Hf and Zr, when activated by MAO at 50-80 degrees C, gen

123 f the molecular weight distribution (MWD) of Hf-bound polymers via UV-GPC analysis.

124 rm is produced by solution phase reaction of Hf(NEtMe)4 with ammonia followed by low-temperature pyro

125 sed for deprotonation of YHf and transfer of Hf+ against the thermodynamic potential.

126 We propose that the transfer of Hf+ from formate to the active site base Y- is thermodyn

127 tion at the Hf center, and chain transfer of Hf-bound polymers to ZnEt2 is fast and quasi-irreversibl

128 Large-area devices (>0.2 mm(2)) on Hf-SAND (6.5 nm thick) achieve mA on currents at ultralo

129 Based on Hf-W chronometry on Allende chondrules and matrix, this

130 mbient (400 degrees C) has limited impact on Hf-SAND leakage densities (<10(-6) A/cm(2) at +/-2 V) an

131 derived tricarboxylate ligands (Hf-BPY-Ir or Hf-BPY-Ru; bpy=2,2'-bipyridine, ppy=2-phenylpyridine) an

132 plexes [Cp*2MCH3](+)[B(C6F5)4](-) (M = Zr or Hf) with trimethylsilyl(diarylphosphino)acetylenes Ar2P-

133 organic frameworks (MOFs), M-MTBC (M = Zr or Hf), constructed from the tetrahedral linker methane-tet

134 oxide complexes [(PNP)M(CH3)2(OAr)] (M=Zr or Hf; PNP(-)=N[2-P(CHMe2)2-4-methylphenyl]2); Ar=2,6-iPr2C

135 Here we present new Sr-Nd-Pb-Hf isotope data from the older parts of this hotspot tra

136 ns and their host oxide gabbro have positive Hf isotope compositions (epsilonHf = +15.7-+12.4), sugge

137 educed Mo(IV) state with the formate proton, Hf+, transferring to a nearby base Y-.

138 how that there is a more positive radiogenic Hf isotopic composition with clay-sized fractions than t

139 In the halichondrin C series, Hf(OTf)4 was used to convert the double oxy-Michael prod

140 The sizable Hf-SAND capacitances are attributed to relatively large

141 The clay-sized Hf-Nd isotopic compositions of the desert samples from t

142 lso exists in MC-ICPMS, e.g., Nd, Ce, W, Sr, Hf, Ge, Hg, and Pb isotopes, the nature of mass bias for

143 H interaction and formation of a stabilizing Hf-arene interaction.

144 anoscale metal-organic framework (nMOF), TBC-Hf, and a small-molecule immunotherapy agent that inhibi

145 arbon nanotube transistors were used to test Hf-SAND utility in electronics and afforded record on-st

146 nd a well-defined correlation between the Th/Hf and (176)Hf/(177)Hf ratios in chondrites that reflect

147 The Hf-Nd isotopic compositions of dust in the North Pacific

148 the C-C bond of a cyclopropane ring and the Hf.

149 not influence the rate of propagation at the Hf center, and chain transfer of Hf-bound polymers to Zn

150 l similarity of the Hf and Zr complexes, the Hf complexes generate more highly stereoselective cataly

151 Using this relationship, we estimate the Hf/W ratio in Mars' mantle to be 3.51 +/- 0.45.

152 ggests optimal activation conditions for the Hf pre-catalyst in the presence of the activator [Ph3C][

153 riers than corresponding insertions into the Hf-alkyl bond.

154 culations show that such insertions into the Hf-aryl bond have lower barriers than corresponding inse

155 e driving forces for this insertion into the Hf-aryl bond include elimination of an eclipsing H-H int

156 thyl, consistent with 1,2-insertion into the Hf-aryl bond.

157 itially undergoes monomer insertion into the Hf-naphthyl bond, which permanently modifies the ligand

158 Despite the structural similarity of the Hf and Zr complexes, the Hf complexes generate more high

159 n of Cl upon increase in coordination of the Hf atom of the precursor.

160 osely isostructural; the bond lengths of the Hf complex are slightly shorter, but the maximum deviati

161 ed, demonstrating the flexible nature of the Hf(IV)-BHA system.

162 sponding bulk sample and a decoupling of the Hf-Nd couplets in the clay formation during the weatheri

163 We suggest that the Hf-W timescale reflects the principal phase of core-form

164 g to a large uncertainty associated with the Hf/W ratio of the Martian mantle and as a result, contra

165 These Hf-SAND multilayers are grown from solution in ambient w

166 Thus, Hf-bound polymeryls are selectively labeled in the prese

167 is observed that the Ni interstitial and Ti,Hf/Sn antisite defects are collectively formed, leading

168 Moving down the periodic table (Ti to Hf) has a marked effect on the experimental transition i

169 Variations in zircon Hf and U/Yb reaffirm that tin belt magmas contain greate

170 ctive metal complexes M(CH(2)Ph)(4) (M = Zr, Hf) and multiple activation conditions represent a new h

171 orks (MOFs), NU-1000 and UiO-66, for M = Zr, Hf.

172 3-ONa)4H6](6-) nodes in M(III)H-BTC (M = Zr, Hf; BTC is 1,3,5-benzenetricarboxylate) via bimetallic r

173 afnium polyazides [PPh4 ]2 [M(N3 )6 ] (M=Zr, Hf) were obtained in near quantitative yields from the c

174 carbon covalence in (C5H5)2MCl2 (M = Ti, Zr, Hf) has been evaluated using carbon K-edge X-ray absorpt

175 of oxygen-functionalized M2CO2 (M = Ti, Zr, Hf) MXenes are investigated using first-principles calcu

176 M(NMe(2))(4) (M = Ti, Zr, Hf) were found to react with H(2)SiR'Ph (R' = H, Me, Ph)

177 [M(N3 )5 ](-) and [M(N3 )6 ](2-) (M=Ti, Zr, Hf) were studied by quantum chemical calculations at the

178 r)]}(2)(mu-N(2)) compounds where M = Ti, Zr, Hf, Ta, Mo, and W.

179 c structures of O(h)-MCl(6)(2-) (M = Ti, Zr, Hf, U) and C(4v)-UOCl(5)(-), and to determine the relati

180 actinide hexahalides, MCl6(2-) (M = Ti, Zr, Hf, U).

181 xes {PhB(C5H4)(Ox(R))2}M(NMe2)2 (M = Ti, Zr, Hf; Ox(R) = 4,4-dimethyl-2-oxazoline, 4S-isopropyl-5,5-d

182 large family of materials (WHM with W = Zr, Hf; H = Si, Ge, Sn; M = O, S, Se, Te) with identical ban

183 Similar to the (Zr,Hf)NiSn based solid solutions, the unsubstituted ZrNiSn

184 They are the first examples of Zr/Hf MOFs with tetrahedral linkers.

185 stitution of the 8-connected nodes by the Zr/Hf clusters yielded MOFs with large octahedral interstit