Syntheses, spectroscopy and fluxional behavior of the η3-crotyl, C3H4(CH3), pyrolidinyldithiocarbamate molybdenum complexes: crystal structure of exo-[Mo{η3-C3H4(CH3)}(η2-S2CNC4H8)(CO)(η2-dppm)]

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Note

Syntheses, spectroscopy and fluxional behavior of the h

3

-crotyl,

C

3

H

4

(CH

3

), pyrolidinyldithiocarbamate molybdenum complexes:

crystal structure of exo-[Mo{h

3

-C

3

H

4

(CH

3

)}(h

2

-S

₂

CNC

₄

H

₈

)(CO)(h

2

-dppm)]

Kuang-Hway Yih

a,

*

, Gene-Hsiang Lee

b

, Shou-Ling Huang

b

, Yu Wang

c

a_{Department of Applied Cosmetology, Hung Kuang University, 34 Chung Chi Road, Shalu, Taichung Hsien, Taiwan 433} b_{Instrumentation Center, College of Science, National Taiwan University, Taipei, Taiwan 106}

c_{Department of Chemistry, National Taiwan University, Taipei, Taiwan 106}

Received 14 October 2002; accepted 27 November 2002

Abstract

The endo - and exo -complexes [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-diphos)] (diphos: dppm /

{bis(diphenylphosphi-no)methane} (2); dppe /{1,2-bis(diphenylphosphino)ethane} (3) are prepared by reacting the 16-electron complex [Mo{h3

-C3H4(CH3)}(h2-S2CNC4H8)(CO)2] (1) with diphos in refluxing acetonitrile. The orientations of endo and exo are defined in such a

way that the open face of the allyl group and carbonyl group are in the same direction in the former and in the opposite direction in the latter. The variable temperature 1H NMR was used to confirm that there was no allyl rotation behavior of endo l/exo

interconversion of 2 before the thermal decomposition. X-ray crystal structure of exo -2 has been employed to elucidate the exo orientation and the methyl moiety of the allyl ligand is found to orient away from the dppm ligand.

Keywords: Endo-, exo-orientations; h3_{-Crotyl molybdenum complexes; Pyrolidinyldithiocarbamate ligand; Crystal structures}

1. Introduction

The X-ray crystallographic studies[1]and fluxionality [2]of the complexes with [Mo(h3-allyl)(CO)2(L2)X] (L2:

pyrazolylborate, b-diketonate, dithiocarbamate, X: neu-tral monodentate ligand; L2: diphos, pyridylphosphane,

X: halide) have so far revealed three different solid-state structures as depicted inFig. 1(A /C) and attributed to

the intramolecular trigonal twist (A /B), in which the

rotation of the triangular face formed by the L2X groups

is relative to the face formed by the allyl and the two carbonyl groups. Only a few studies have been focused on the derivatives of complexes [Mo(h3-allyl)(CO)(h2

-S2)X]. Recently, we reported the reactions of [Mo(h3

-allyl)(CO)2(h2-S2)X] (S2/Et2NCS2, C4H8NCS2; S2/

(EtO)2PS2, X /CH3CN) with diphos (diphos /dppm,

dppe, dppa) to produce the conformational endo , exo -complexes [Mo(h3-C3H5)(h2-S2)(CO)(h2-diphos)] [3]

and investigated the rotational behavior of allyl group in these complexes. We have studied the relation of the diphos ligands, the ratios, and free allyl rotational energy of the endo -, exo -complexes showed the dppe ligand improves the formation of the endo -[Mo(h3 -C3H5){h2-S2P(OEt)2}(CO)(h2-dppe)] as the sole

pro-duct[4].

As an extension of our recent work on the stereo-selective formation of the sole conformer, we employ crotyl, C3H4(CH3), to investigate the dependence of the

ratio and interconversion of the endo - and exo -con-formers.

* Corresponding author. Fax: /886-4-2632-10-46. E-mail address: khyih@sunrise.hkc.edu.tw(K.-H. Yih).

www.elsevier.com/locate/ica

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2. Result and discussion

2.1. Synthesis of (h3-crotyl)(dicarbonyl)(h2 -pyrolidinyldithiocarbamate)molybdenum(II) complex [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)2] (1)

Treatment of [Mo(CH3CN)2{h3-C3H4(CH3)}(CO)2

-Br] with NH4(S2CNC4H8) in MeOH at room

tempera-ture resulted in a replacement reaction, affording the 16-electron complex [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8

)-(CO)2] (1) with 88% isolation yield. Preparation of the

16-electron complexes [Mo(h3-allyl)(CO)2(h2-S2CNR)]

from the reactions of [Mo(CH3CN)2(h3-allyl)(CO)2Br]

with NaS2CNR (R /C4H8, Et2) have been reported by

Shiu et al. [5]. The air-sensitive yellow compound 1 is soluble in polar solvents and insoluble in n -hexane and diethyl ether. Complex 1 is more soluble and air-sensitive than the non-methylated complex [Mo(h3 -C3H5)(h2-S2CNC4H8)(CO)2]. The analytical data of 1

are in agreement with the formulation. FAB mass spectrum of 1 shows a parent peak with the typical Mo isotope distribution corresponding to the [M] molecular mass. The IR spectrum of 1 shows two carbonyl-stretchings with equal intensity, indicating that the two carbonyls are mutually cis . Due to the methyl moiety, the room temperature 1H NMR spec-trum of 1 exhibits five sets of resonances of the C3H4(CH3) ligand which is typical of the ABCDX spin

patterns of unsymmetrical h3-allyl metal complexes. Only one resonance of the Hsyn has been observed in

1

H NMR spectra, which the methyl group occupies the syn position of the allyl group (Scheme 1). In the

13

C{1H} NMR spectrum of 1, three singlet resonances appear in the carbonyl region. Two relative down-field

singlet resonances at d 229.9 and 231.4 are attributed to two chemically non-equivalent carbonyl groups and the relative up-field singlet resonance at d 202.0 is assigned to the carbon atom of the CS2of the C4H8NCS2ligand.

2.2. Synthesis of endo - and exo -(carbonyl)(h3 -crotyl)(h2-diphos)(h2 -pyrolidinyldithiocarbamate)-molybdenum(II) complex [Mo{h3-C3H4(CH3)}(h2

-S2CNC4H8)(CO)(h2-dppm)] (2) and [Mo{h3

-C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppe)] (3)

The reactions of complexes [Mo(h3-allyl)(CO)2

-(dithio)L] with phenanthroline, phenylacetylene [6]and diphos [3] have been reported. Thus, treatment of [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)2] (1) with

dppm or dppe in refluxing acetonitrile yields mixtures of endo -, exo -[Mo{h3-C3H4(CH3)}(h2-S2CNC4H8

)-(CO)(h2-dppm)] (2) with endo :exo ratios of 1:20 or endo -, exo -[Mo{h3-C3H4(CH3)}(h2-S2CNC4H8

)(CO)-(h2-dppe)] (3) with endo :exo ratios of 2:1 (Scheme 1). The air-stable yellow /orange compounds 2 and 3 are

soluble in dichloromethane and in acetonitrile and insoluble in diethyl ether and in n -hexane. The orienta-tions of endo and exo are defined to the open face of the allyl group and carbonyl group in the same direction in the former and in the opposite directions in the latter. The spectroscopic and analytical data of 2 and 3 are obtained. In the FAB mass spectra, base peaks with the typical Mo isotope distribution are in good agreement with the [M/CO] molecular masses of 2 and 3. The IR

spectra of 2 and 3 show one terminal carbonyl-stretch-ing band at 1770 and 1790 cm1, respectively, although both isomers are known to be present in different ratios. The mixtures of endo , exo -2 or endo , exo -3 are able to distinguish from different 31P{1H} /

31

P{1H} coupling constants. The31P{1H} NMR spectrum of 2 shows endo resonances at d 9.7 and 36.1 (with 2J (PP) /52.1 Hz)

and exo resonances at d 5.0 and 30.0 (with 2J (PP) /

60.7 Hz). Compared to the31P{1H} NMR spectrum and the structure of the complex [Mo(h3-C3H5)(CO)(h2

-S2CNC4H8)(h2-dppm)] [3], the resonances appear in

relative up-field with large coupling constant is assigned to the exo -orientation and in the relative down-field

Fig. 1. Three possible structures A, B and C for [Mo(h3

-C3H5)(CO)2(L2)X].

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with small coupling constant is assigned to the endo -orientation. Because of the different ratios of endo :exo -2 (1:20), the1H and 13C{1H} NMR spectra of the major product exo -2 can be assigned unambiguously from the

1

H /1H COSY and 1H /13C COSY experiments. From Fig. 2, the two Hanti protons appear at d 2.29 (d,

2

J (HH) /11.7 Hz) and 2.35 (dd,

2

J (HH) /6.93 Hz,

3

J (PH) /19.2 Hz) and the Hsyn proton appears at d

3.12 ppm, which is overlapped by one proton of the NCH2 moiety of the dithiocarbamate ligand. Two

resonances are shown at the lowest field in the

13

C{1H} NMR spectrum of 2, the relative down-field triplet resonance is attributed to the carbon atom of the carbonyl group that is coupled by two phosphorus atoms and the relative up-field singlet resonance is attributed to the CS2of the dithiocarbamate ligand.

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Compared to the ratios of endo -, exo -[Mo{h3 -C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)] (2) (1:20),

endo -, exo -[Mo(h3-C3H5)(h2-S2CNC4H8)(CO)(h2

-dppm)] (1:4) and endo -, exo -[Mo{h3-C3H4(CH3)}(h2

-S2CNC4H8)(CO)(h2dppe)] (3) (2:1) and endo , exo

-[Mo(h3-C3H5)(h2-S2CNC4H8)(CO)(h2-dppe)] (6:1), it is

clear that the stereoselective formation of the exo -product by the methyl moiety of the allyl ligand is improved.

2.3. Variable temperature1H and31P{1

H}NMR

experiments of endo - and exo -complex 2

Variable temperature 1H NMR experiments can be used to study the fluxional behavior of non-rigid complexes. For example, the rearrangement involving a p /s/p [7] process of complexes [Tp?Mo(CO)2(allyl)]

and intramolecular trigonal twist behavior of complexes [M(h3-C3H5)(CO)2(diphos)I][8](M /Mo, W; diphos /

dppm, dppe). Recently, we have described the allyl rotational behavior of complexes [Mo(h3-C3H5)(h2

-S2CNC4H8)(CO)(h2-diphos)] (diphos /dppm, dppe).

Thus, in order to investigate the fluxionality of the crotyl complex endo -, exo -2, the variable temperature

1

H and 31P{1H} NMR spectra were recorded in the range of 298 /328 K. In the range of 298 /318 K, the1H

and 31P{1H} NMR spectra are not changed and the ratio is retained. Surprisingly, the 31P{1H} NMR spectra show only one resonance at d 10.2 ppm (Section 4, spectrum A) and the1H NMR spectra show organic alkene resonances at d 4.8 /5.8 at 323 K. From the

above description, it is clear that the crotyl group breaks away from the metal complex. The decomposition may be due to the steric hindrance of the crotyl group in the allyl rotational process. Formation of the endo -, exo -2 is believed to proceed via one of the phosphorus coordina-tion at the axial posicoordina-tion trans to the crotyl ligand of 1 to afford a six coordination complex, followed by the crotyl rotation to form the endo and exo orientations and then the other phosphorus replace the carbonyl group to form the endo - and exo -2.

2.4. X-ray structure determination of exo -[Mo{h3 -C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)] (2)

In order to confirm the orientation of the methyl group, we have performed an X-ray diffraction study of 2 at 150 K. TheORTEPplot of 2 is shown inFig. 3. In the

structure, the coordination geometry around the mo-lybdenum atom is approximately an octahedron with the two sulfur atoms, two phosphorus atoms, carbonyl and the crotyl group occupying the six coordination sites. The structure confirms an unequivalent allyl group and the methyl moiety of the allyl ligand is oriented toward CO group. One of the sulfur atoms of dithio ligand is trans to the diphos: S(1) /Mo /P(2), 143.93(4)8,

while the other is trans to carbonyl: S(2) /Mo /C(1),

169.11(12)8. The S /Mo /S angle of 68.958(17)8 in 2 is

similar to 68.459(17)8 in complex exo -[Mo(h3-C3H5)(h2

-S2CNC4H8)(CO)(h2-dppm)] within the experimental

errors. The Mo /C(2), C(3) and C(4) bond distances

are 2.329(4), 2.337(4) and 2.404(4) A˚ , respectively. The Mo /S(1) distance of 2.5324(10) A˚ (trans to phosphorus)

is clearly shorter than Mo /S(2) of 2.6197(10) A˚ (trans

to CO) because of the greater trans effect induced by the CO group than the diphos ligand.

The bond distances and intercarbon angle of allyl group in exo -2 (1.393(6), 1.393(6) A˚ and 120.5(4)8) are in the range of related MoII-allylic compounds (1.31 /

1.42 A˚ , 115/1258) [9]. Selected bond distances and

angles for exo -[Mo{h3-C3H4(CH3)}(h2-S2CNC4H8

)-(CO)(h2-dppm)] (2) and exo -[Mo(h3-C3H5)(h2-S2

CN-C4H8)(CO)(h2-dppm)] are listed in Table 3. From this

table, the Mo /C1 bond distance of 2.404(4) A˚ in exo-2

is significantly longer than that of 2.339(2) A˚ in the non-methylated allyl complex exo -[Mo(h3-C3H5)(h2

-S2CNC4H8)(CO)(h2-dppm)] due to the steric hindrance

of the methyl moiety.

2.5. Conclusion

We employ two diphos ligands and crotyl ligand to investigate the dependence of the ratios and interconver-sion of the endo - and exo -conformers. The dppm ligand improves the formation of exo -product, whereas the dppe ligand improves the formation of endo -product. The exo -complexes show large J (PP) coupling constant than the endo -complexes. The resonances of dppm complex appear in relative up-field for the exo

-orienta-Fig. 3. An ORTEP drawing with 50% thermal ellipsoids and

atom-numbering scheme for the complex exo -[Mo{h3_-C

3H4(CH3)}(h2

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tion and dppe complex appear in the relative up-field for the endo -orientation. Steric effect of the crotyl ligand improves the formation of exo -products and does not induce allyl endo l/exo interconversion of 2 before the

thermal decomposition.

3. Experimental 3.1. Materials

All manipulations were performed under nitrogen using vacuum-line, drybox, and standard Schlenk tech-niques. NMR spectra were recorded on an AM-300 or an AM-500 WB FT-NMR spectrometer and are re-ported in units of parts per million with residual protons in the solvent as an internal standard (CDCl3, d 7.24).

IR spectra were measured on a Nicolate Avator-320 instrument and referenced to polystyrene standard, using cells equipped with calcium fluoride windows. MS spectra were recorded on a JEOL SX-102A spectro-meter. Solvents were dried and deoxygenated by reflux-ing over the appropriate reagents before use. n -Hexane, diethyl ether, THF and benzene were distilled from sodium-benzophenone. Acetonitrile and dichloro-methane were distilled from calcium hydride, and methanol was distilled from magnesium. All other solvents and reagents were of reagent grade and used as received. Elemental analyses and X-ray diffraction studies were carried out at the Regional Center of Analytical Instrument located at the National Taiwan University. Mo(CO)6and C3H4(CH3)Br were purchased

from Strem Chemical, C4H8NCS2NH4, dppm, and dppe

were purchased from Merck. 3.2. (h3-Crotyl)(dicarbonyl)(h2

-pyrolidinyldithiocarbamate)molybdenum(II) complex [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)2] (1)

MeOH (20 ml) was added to a flask (100-ml) contain-ing NH4S2CNC4H8 (0.164 g, 1.0 mmol) and

[Mo(CH3CN)2{h 3

-C3H4(CH3)}(CO)2Br] (0.370 g, 1.0

mmol). The solution was stirred for 5 min at room temperature, and a yellow /orange solids 1 were formed

which were isolated by filtration (G4), washed with n -hexane (2 /10 ml) and subsequently drying under

vacuum yielding [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8

)-(CO)2] (1) (0.31 g, 88%). Further purification was

accomplished by recrystallization from 1/10 CH2Cl2/n

-hexane. Spectroscopic data of 1 are as follows. IR (KBr, cm1): n (CO) 1927(vs), 1851(vs). 1H NMR (500 MHz, CDCl3, 298 K): d 1.10 (d,3J (HH) /9.2 Hz, 1H, Hanti ), 1.64 (m, 1H, Hanti ), 1.80 (d, 4J (HH) /6.3 Hz, 3H, CH3), 1.91 (s, 4H, NCH2CH2), 2.94 (d, 3J (HH) /6.4 Hz, 1H, Hsyn ), 3.52 (s, 4H, NCH2), 3.75 (m, 1H, Hc ). 13 C{1H} NMR (75 MHz, CDCl3, 298 K): d 18.5 (s, C H3), 24.7 (s, NCH2C H2), 50.2 (s, NC H2), 55.0, 73.5 (s, /CH2), 77.0 (s, /CH), 202.0 (s, NCS2), 229.9, 231.4 (s,

CO). MS (FAB, NBA, m /z ) 355 (M), 327 (M/CO),

299 (M/2CO). Anal . Calc. for C₁₁H₁₅NO₂S₂Mo: C,

37.39; H, 4.28; N, 3.97%. Found: C, 37.42; H, 4.40; N, 3.88%.

3.3. Endo -, exo -(carbonyl)(h3-crotyl)(h2-diphos)(h2 -pyrolidinyldithiocarbamate)molybdenum(II) complex [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)]

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MeCN (20 ml) was added to a flask (100-ml) contain-ing dppm (0.384 g, 1.0 mmol) and [Mo{h3 -C3H4(CH3)}(h2-S2CNC4H8)(CO)2] (1) (0.353 g, 1.0

mmol). The solution was refluxed for 1 h, and an IR spectrum indicated completion of the reaction. After removal of the solvent in vacuo, the residue was redissolved with CH2Cl2 (10 ml). n -Hexane (15 ml)

was added to the solution and a yellow /orange solids

endo -, exo -2 were formed which were isolated by filtration (G4), washed with n -hexane (2 /10 ml) and

subsequently drying under vacuum yielding endo , exo -[Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)]

(2) (0.62 g, 87%). Further purification was accomplished by recrystallization from 1/10 CH2Cl2/n -hexane.

Spec-troscopic data of endo -, exo -2 are as follows. IR (KBr, cm1): n (CO) 1770(vs). MS (FAB, NBA, m /z ) 721.5 (M/CO). Anal . Calc. for C35H37NOP2S2Mo: C,

59.23; H, 5.26; N, 1.97%. Found: C, 59.56; H, 5.10; N, 1.84%.31P{1H} NMR (202 MHz, CDCl3, 298 K): endo -2: d 9.7, 36.1 (d,2J (PP) /52.1 Hz, dppm). exo -2: d 5.0, 30.0 (d,2J (PP) /60.7 Hz, dppm). exo -2:1H NMR (500 MHz, CDCl3, 298 K): d 1.60, 1.75, 1.77, 1.78 (m, 4H, NCH2CH2), 2.26 (d,4J (HH) /5.60 Hz, 3H, CH₃), 2.29 (d, 3J (HH) /11.7 Hz, 1H, Hanti ), 2.35 (dd,3J (HH) / 6.93 Hz,3J (PH) /19.2 Hz, 1H, Hanti ), 2.68, 3.12, 3.26, 3.44 (m, 4H, NCH2), 3.12 (br, 1H, Hsyn ), 4.01 (dt, 2 J (HH) /15.1 Hz, 2J (PH) /9.0 Hz, 1H, PCH₂), 4.26 (dd, 2J (HH) /15.1 Hz, 2J (PH) /8.4 Hz, 1H, PCH₂), 4.70 (m, 1H, Hc ). 13C{1H} NMR (125 MHz, CDCl3, 298 K): d 20.0 (s, CH3), 24.5, 24.9 (s, NCH2C H2), 42.9 (t, J (PC) /19.4 Hz, PCH₂), 48.7, 49.5 (s, NCH₂), 51.9 (d, 2J (PC) /15.1 Hz, C HCH3), 87.6 (d, 2J (PC) /9.6 Hz, C H2/CH), 102.5 (s, CH2/C H), 126.3 /134.5 (Ph), 204.8 (s, CS2), 228.3 (t,2J (PC) /12.6 Hz, CO).

3.4. Endo -, exo -(carbonyl)(h3-crotyl)(h2-diphos)(h2 -pyrolidinyldithiocarbamate)molybdenum(II) complex [Mo{h3-C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppe)]

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Complex endo -, exo -[Mo{h3-C3H4(CH3)}(h2

-S2CNC4H8)(CO)(h2-dppe)] (3) was synthesized using

the same procedure as that used in the synthesis of 2 by employing 1 and dppe. The yields are 95% for 3.

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Spectroscopic data of endo -, exo -3 are as follows. IR (KBr, cm1): n (CO) 1790(vs). 1H NMR (500 MHz, CDCl3, 298 K): d 1.46, 1.59, 1.66 (m, 4H, NCH2CH2), 1.98 (s, 3H, CH3), 2.08 (d,4J (HH) 6.06 Hz, 2H, Hanti ), 2.25 (br, 1H, Hsyn ), 2.76, 2.85, 3.25 (m, 4H, NCH2), 2.49, 2.98 (m, 4H, PCH2), 4.06 (m, 1H, Hc ). 13C{1H} NMR (75 MHz, CDCl3, 298 K): d 18.8, 19.7 (s, CH3), 24.6, 24.9 (s, NCH2C H2), 26.2 (t, J (PC) /19.8 Hz, PCH2), 48.7, 49.2 (s, NCH2), 77.2 (s, C H2/CH), 88.6 (s, CH2/C H), 125.4 /136.1 (Ph), 203.8, 205.7 (s, CS₂). MS

(FAB, NBA, m /z ) 697.7 (M/CO). Anal . Calc. for

C36H39NOP2S2Mo: C, 59.74; H, 5.43; N, 1.94%. Found:

C, 59.66; H, 5.20; N, 1.78%.31P{1H} NMR (202 MHz, CDCl3, 298 K): endo -3: d 56.2, 85.0 (br, dppm). exo -3:

d 65.0, 88.3 (d, 2J (PP) /29.8 Hz, dppm).

3.5. X-ray crystallography

Single crystal of exo -2 suitable for X-ray diffraction analysis was grown by recrystallization from 20/1 n -hexane/CH2Cl2. The diffraction data were collected at

room temperature on an Enraf /Nonius CAD4

diffract-ometer equipped with graphite-monochromated Mo Ka (l /0.71073 A˚ ) radiation. The raw intensity data were

converted to structure factor amplitudes and their esd’s after corrections for scan speed, background, Lorentz, and polarization effects. An empirical absorption

cor-rection, based on the azimuthal scan data, was applied to the data. Crystallographic computations were carried out on a Microvax III computer using the NRCC-SDP-VAXstructure determination package[10].

A suitable single crystal of 2 was mounted on the top of a glass fiber with glue. Initial lattice parameters were determined from 24 accurately centered reflections with u values in the range from 2.08 to 27.508. Cell constants and other pertinent data were collected and are recorded inTable 1. Reflection data were collected using the u /2u scan method. The u scan angle was determined for each reflection according to the equation 0.709/0.35 tan u .

Three check reflections were measure every 30-min throughout the data collection and showed no apparent decay. The merging of equivalent and duplicate reflec-tions gave a total of 26 013 unique measured data, of which 7347 reflections with I /2s (I ) were considered.

The first step of the structure solution used the heavy-atom method (Patterson synthesis), which revealed the positions of metal atoms. The remaining atoms were found in a series of alternating difference Fourier maps and least-squares refinements. The quantity minimized by the least-squares program was w (jFoj/jFcj)2, where

w is the weight of a given operation. The analytical forms of the scattering factor tables for the neutral atoms were used [11]. The non-hydrogen atoms were

Table 1

Crystal data and refinement details for complex exo -[Mo{h3

-C3H4(CH3)}(h 2

-S2CNC4H8)(CO)(h 2

-dppm)] (2)

Empirical formula C35H37NOP2S2Mo

Formula weight 709.66

Crystal system Trigonal

Crystal size (mm) 0.28 /0.25 /0.15 Space group P 31 a (A˚ ) 11.2966(1) b (A˚ ) 11.2966(1) c (A˚ ) 22.6575(2) g (8) 120 V (A˚3) 2504.02(4) Z 3 T (K) 150(1) DCalc.(g cm3) 1.412 m(Mo Ka) (mm1₎ _0.642 F (000) 1098 uRange 2.08 /27.50 h ,k ,l range /14 0/14, /14 0/14, /29 0/26 Reflections collected 26 013 Observed data [I /2s (I )] 7347 No. of parameters 398 Ra _0.040 Rwb 0.090

Transmission (min, max) 0.911, 0.824

Quality-of-fitc 1.064

D(D-map) max, min (e A˚3) /0.594; 0.774

a _R /SjjFoj/jFcjj/SjFoj. b _R w/[Sv (jFoj/jFcj)2]1/2; v /1/s2(jFoj). c _{Quality-of-fit} /[Sv (jFoj/jFcj)2/(Nreflections/Nparameters)]1/2. Table 2

Selected bond distances (A˚ ) and angles (8) for exo -[Mo{h3 -C3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)] (2) Bond distances Mo /S(1) 2.5324(10) C(2) /C(3) 1.393(6) Mo /S(2) 2.6197(10) C(3) /C(4) 1.393(6) Mo /C(1) 1.902(4) C(4) /C(5) 1.495(6) Mo /C(2) 2.329(4) C(1) /O(1) 1.185(5) Mo /C(3) 2.337(4) P(1) /C(11) 1.841(4) Mo /C(4) 2.404(4) P(2) /C(11) 1.838(4) Mo /P(1) 2.4754(10) S(1) /C(6) 1.726(4) Mo /P(2) 2.4298(10) S(2) /C(6) 1.704(4) C(6) /N(1) 1.333(5) Bond angles S(1) /Mo /S(2) 68.68(3) S(l) /C(6) /S(2) 115.9(2) S(1) /Mo /C(1) 100.52(12) S(1) /C(6) /N(1) 122.0(3) S(1) /Mo /C(2) 135.58(10) S(2) /C(6) /N(1) 122.1(3) S(1) /Mo /C(3) 113.30(12) S(1) /Mo /P(2) 143.93(4) S(1) /Mo /C(4) 79.51(10) S(1) /Mo /P(1) 77.55(3) S(2) /Mo /C(1) 169.11(12) S(2) /Mo /P(1) 89.81(3) S(2) /Mo /C(2) 86.4(12) S(2) /Mo /P(2) 101.74(3) S(2) /Mo /C(3) 101.30(11) C(1) /Mo /P(1) 89.13(11) S(2) /Mo /C(4) 84.82(10) C(1) /Mo /P(2) 87.86(12) C(1) /Mo /C(2) 101.12(16) P(1) /Mo /P(2) 67.48(3) C(1) /Mo /C(3) 81.35(15) P(1) /C(11)/P(2) 95.58(18) C(1) /Mo /C(4) 91.93(15) C(5) /C(4) /Mo 70.3(2) C(2) /Mo /P(1) 140.78(11) C(6) /N(1) /C(7) 123.9(4) C(2) /Mo /P(2) 75.11(10) C(6) /N(1) /C(10) 123.4(4) C(3) /Mo /P(2) 102.60(12) Mo /S(2) /C(6) 86.40(14) C(4) /Mo /P(1) 156.83(10) Mo /S(1) /C(6) 88.79(14) C(3) /Mo /P(1) 166.63(11) C(7) /N(1) /C(10) 112.2(4) C(4) /Mo /P(2) 135.68(10) Mo /C(1) /O(1) 178.6(3)

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refined anisotropically. Hydrogen atoms were included in the structure factor calculations in their expected positions on the basis of idealized bonding geometry but were not refined in least squares. The final residuals of this refinement were R /0.040 and R_w/0.090. Selected

bond distances and angles are listed inTable 2.

4. Supplementary material

Tables of complete atomic coordinates, bond lengths and angles, thermal parameters (4 pages) and listing of

structure factors (15 pages) are available from the author K.H. Yih upon request.

Acknowledgements

We thank the National Science Council of the Republic of China for support.

References

[1] (a) R.H. Fenn, A.J. Graham, J. Organomet. Chem. 37 (1972) 137; (b) A.J. Graham, D. Akrigg, B. Sheldrick, Cryst. Struct. Com-Table 3

Selected bond distances (A˚ ) and angles (8) for exo -[Mo{h3_-C

3H4(CH3)}(h2-S2CNC4H8)(CO)(h2-dppm)] (2) and exo -[Mo(h3-C3H5)(h2

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mun. 24 (1985) 173;

(c) F.A. Cotton, C.A. Murillo, B.R. Stults, Inorg. Chim. Acta 7 (1977) 503;

(d) C.A. Cosky, P. Ganis, G. Avatabile, Acta Crystallogr. B 27 (1971) 1859;

(e) J.W. Faller, D.F. Chodosh, D. Katahira, J. Organomet. Chem. 187 (1980) 227;

(f) F.A. Cotton, M. Jeremic, A. Shaver, Inorg. Chim. Acta 6 (1972) 543.

[2] (a) A.J. Graham, R.H. Fenn, J. Organomet. Chem. 17 (1969) 405; (b) A.J. Graham, R.H. Fenn, J. Organomet. Chem. 25 (1970) 173; (c) F.A. Cotton, B.A. Frenz, A.G. Stanislowski, Inorg. Chim. Acta 7 (1973) 503;

(d) F. Dewans, J. Dewailly, J. Meuniert-Piret, P. Piret, J. Organomet. Chem. 76 (1974) 53.

[3] K.H. Yih, G.H. Lee, S.L. Huang, Y. Wang, Organometallics 21 (2002) 5767.

[4] K.H. Yih, G.H. Lee, Y. Wang, Inorg. Chem. Commun. 3 (2000) 458.

[5] K.B. Shiu, K.H. Yih, S.L. Wang, F.L. Liao, J. Organomet. Chem. 420 (1991) 359.

[6] K.H. Yih, G.H. Lee, S.L. Huang, Y. Wang, J. Organomet. Chem. 658 (2002) 191.

[7] (a) S.K. Chowdhury, M. Nandi, V.S. Joshi, A. Sarkar, Organo-metallics 16 (1997) 1806 (and references cited therein);

(b) M. Kollmar, B. Goldfuss, M. Reggelin, F. Rominger, G. Helmchen, Chem. Eur. J. 7 (2001) 4913.

[8] J.W. Faller, D.A. Haitko, R.D. Adams, D.F. Chodosh, J. Am. Chem. Soc. 101 (1979) 865.

[9] (a) R.H. Fenn, A.J. Graham, J. Organomet. Chem. 37 (1972) 137; (b) A.J. Graham, D. Akrigg, B. Sheldrick, Cryst. Struct. Com-mun. 24 (1976) 173;

(c) F.A. Cotton, C.A. Murillo, B.R. Stults, Inorg. Chim. Acta 7 (1977) 503;

(d) C.A. Cosky, P. Ganis, G. Avatabile, Acta Crystallogr. B 27 (1971) 1859;

(e) J.W. Faller, D.F. Chodosh, D. Katahira, J. Organomet. Chem. 187 (1980) 227;

(f) F.A. Cotton, M. Jeremic, A. Shaver, Inorg. Chim. Acta 6 (1972) 543.

[10] E.J. Gabe, F.L. Lee, Y. Lepage, G.M. Shhelldrick, C. Kruger, R. Goddard (Eds.), Crystallographic Computing 3, Clarendon Press, Oxford, 1985, p. 167.

[11] (a) International Tables for X-ray Crystallography vol. IV, Reidel, Dordrecht, 1974;